First-class REPL, ussl module, machine module for WiPy, stuffed-floats

This release brings first-class REPL support, which now has tab completion,
auto-indent, paste mode, history and _ to hold the last computed value.
There is a new ussl module, and one can now build a standalone unix binary.
The new machine API is implemented in cc3200, with the machine module and
additions to time and os modules.  stmhal contains the beginnings of this
new API, while still retaining full backwards compatibility with the original
pyb API.  unix also includes the new time functions, sleep_ms, sleep_us,
ticks_ms, ticks_us and ticks_diff.  A new object representation is available
which stores single-precision floats within a machine word (using 30-bit
precision), and allows to use float objects without the heap (not enabled in
any port).  There are also bug fixes and general improvements.

py core:
- put compiler state on the C stack
- objrange: bugfix for range_subscr() when index is a slice object
- parsenum: provide detailed error for int parsing with escaped bytes
- mpz: raise NotImplError instead of failing assertion
- mpz: force rhs of mpz_shl_inpl/mpz_shr_inpl to be unsigned
- mpz: fix bignum anding of large negative with smaller positive int
- catch all cases of integer (big and small) division by zero
- allocate parse nodes in chunks to reduce fragmentation and RAM use
- allow to enable inline assembler without native emitter
- fix edge case when constant-folding negation of integer
- emitnative: raise ViperTypeError for unsupported unary ops
- don't generate unnecessary parse nodes for assignment or kwargs
- factor logic when creating parse node from and-rule
- makeqstrdata.py: catch and report case of empty input file
- rename MP_BOOL() to mp_obj_new_bool() for consistency in naming
- add paste mode to friendly REPL, entered via CTRL-E
- rename "Micro Python" to "MicroPython" in REPL, help, readme's and misc
- objarray: allow to create array of void pointers, as extension to CPython
- move constant folding from compiler to parser
- make parser error handling cleaner, less spaghetti-like
- allow to to build MicroPython as a static library
- add support to call __init__ from a builtin module on first import
- implement ptr32 load and store in viper emitter
- fix calc of qstr memory usage, due to new qstr chunk allocation
- remove dependency on printf/fwrite in mp_plat_print
- fix with+for+return bug by popping for-iter when unwinding exc stack
- add option for inline assembler to support ARMv7-M instructions
- add support for _ in REPL to hold last computed value
- stream: allow to reuse is_nonblocking_error()
- add lsl/lsr/asr opcode support to inline Thumb2 assembler
- add mp_obj_is_float function (macro) and use it where appropriate
- move float e/pi consts to objfloat and make mp_obj_float_t private
- make float representation configurable with object representation
- add object repr "C", where 30-bit floats are stuffed in obj word
- nlrthumb: make compatible with Cortex-M0 (ARMv6M instr set)

extmod:
- add modussl, an SSL socket wrapper module based on axTLS

lib:
- axtls: add axtls git submodule, dependency of modussl
- libffi: add libffi as a submodule
- mp-readline: add n_chars argument to mp_hal_erase_line_from_cursor
- make netutils.h available to all ports by default

drivers:
- sdcard: allow up to 5 retries to initialise SD card

tools:
- upip: update to 0.5.9
- pyboard: add -c argument to run a program passed as a string

tests:
- wipy: improve robustness of time test
- wipy: improve robustness of rtc_irq test
- wipy: add machine module tests
- test slicing a range that does not start at zero
- add further tests for mpz code
- allow tests to pass against CPython 3.5
- add test for evaluation order of dictionary key/value pairs
- in pyb RTC tests, check wakeup register values
- add more tests for viper 16/32-bit load/store, and ellipsis
- jni: start adding modjni tests
- extmod: add tests for sleep_ms/us(), ticks_ms/us/diff()

unix port:
- modjni: new_jobject(): Handle null reference
- modjni: call_method(): If name doesn't match, cleanup via goto next_method
- modjni: call_method: Better resource release
- modjni: call_method: Delete done local references in loop
- modjni: implement len() for objects with java.util.List interface
- modjni: fix method argument matching
- modjni: propagate Java exceptions on list access
- modjni: convert Java's IndexOutOfBoundsException to Python's IndexError
- modjni: jobject.__str__/__repr__: Return Java .toString() value
- modjni: jclass.__str__/__repr__: Return Java .toString() value
- add support for building axtls dependency lib
- modjni: after Call*Method(), Java exception should always be checked
- modjni: allow to access fields of objects
- modjni: py2jvalue: Support bool and None values
- modsocket: fix usage of pointers to locals outside scope
- add exit and paste-mode hints to shell startup banner
- modtermios: tcsetattr: if 0 passed for "when" param, treat as TCSANOW
- modjni: call_method: check for Java exception after method return
- modjni: add iteration support for Java List objects
- allow to build against Android down to 1.5
- modos: add statvfs() function
- unix_mphal: implement HAL_Delay() and HAL_GetTick()
- modtime: implement sleep_ms(), sleep_us()
- modtime: implement ticks_ms(), ticks_us() and ticks_diff()
- modos: android Bionic lacks statvfs(), has BSD statfs()

stmhal port:
- in RTC.wakeup, fix setting of wucksel to get correct period
- fix RTC.wakeup so it correctly calculates WUT for large periods
- fix USB CDC-only mode under Windows
- enable REPL auto indent; document paste mode in help()
- allow to set bits resolution for DAC; 8 is default, can have 12
- make USB serial number actually be unique
- early version of machine module for stmhal
- add sleep_{ms,us} and ticks_{ms,us,cpu,diff} to time module
- implement os.dupterm (was pyb.repl_uart)
- uart: if char is not received within timeout, return EAGAIN error
- bring Pin class close to new machine module specification
- rtc: init uses YMD rather than backup register to detect powerup
- enable "all special methods" configuration option

cc3200 port:
- new irq API, affects all classes that provide the irq method
- new WLAN API including test
- implement support for os.dupterm()
- rename pyb module to machine
- disable uheapq and uhashlib
- make auth param positional in wlan.connect
- always reset WLAN after setting the mode
- wiPy SW v1.0.0 release
- in scan results rename 'auth' field to 'sec'
- create wipy module, remove HeartBeat class
- increase stack sizes a bit
- refactor network module to make the server a propper object
- WLAN class can retrieve the existing instance
- enable REPL autoindent
- uart.read() returns EGAIN if no chars available
- make socket.listen([backlog]) compliant with Python 3.5
- enable "all special methods" configuration option
- bump version to 1.1.0

docs:
- update esp8266 documentation to match the code
- describe properly how MCU can be woken from pyb.standby() state
- wipy: update all WiPy docs to reflect the new API
- wipy: add wipy and network.server documentation
- wipy: add wipy tutorials section
- wipy: add usocket and ussl modules' documentation
- wipy: several corrections to the classes in the machine module
- wipy: remove remaining references to 'af', which is now 'alt'
- wipy: add more tutorials and examples

misc:
- travis: build "deplibs" in unix port
- README: document "Ctrl-D" shell exit
- README: document how to enable/build external dependencies

Auto-indent for REPL, jni module for unix, lots more tests

py core:
- make frozensets hashable
- add MICROPY_PY_BUILTINS_FILTER to configure filter builtin
- make slice attributes (start/stop/step) readable (enable via
  MICROPY_PY_BUILTINS_SLICE_ATTRS)
- add support for array('q') and array('Q')
- add stream_tell method, and use for unix and stmhal file tell
- make string formatting 8-bit clean
- treat escaped quotes correctly in REPL continuation
- fix function args when a star-arg is followed by keyword args
- properly classify floats that look like hex numbers (eg 0e0)
- fix calculation of max digit storage for mpz; fix sys.maxsize
- refine SyntaxError for repeated use of global/nonlocal
- raise SyntaxError when unicode char point out of range
- fix error reporting for unexpected end of modulo format str
- fix error type for badly formatted format specifier (is now ValueError)
- raise NotImplementedError for unicode name escape instead of assert
- for str.endswith(s, start) raise NotImplementedError instead of assert
- make str.rsplit(None,n) raise NotImplementedError instead of assert
- handle 'raise X from Y' by issuing a warning that exception chaining is
  not supported
- make it_iternext() recognize IndexError
- only compile function annotations if really needed (for native emitter)
- simplify dispatch of bool binary op
- simplify printing of bytes objects when unicode enabled

lib:
- readline: add auto-indent support; 4 spaces are added at start of line
  to match previous indent, and if previous line ended in colon; backspace
  deletes 4 space if only spaces begin a line

drivers:
- nrf24l01: fix SPI phase setting to match specs of nRF chip

tools:
- upgrade upip to 0.5.8 (adds support for experimental ussl module)

tests:
- explain in README how tests get skipped
- add feature_check dir to collect capability detection scripts
- split byteorder-dependent tests to *_endian.py's
- allow to skip byteorder-dependent tests
- add escaped quotes tests for REPL
- add tests for bool, bytearray, float, exceptions (to improve coverage)
- add test for exception-chaining raise syntax
- add test on set/frozenset equality
- add tests for non-compliant behaviour (relative to CPython)
- add test where __getitem__ raises IndexError to stop iteration
- make io test cleanup after itself by removing 'testfile'
- move int+unicode test to unicode-specific test directory
- wipy: add I2C tests
- wipy: additional tests for when the UART is un-initialized
- wipy: improve UART tests with no pin assignment case
- wipy: remove unneeded dependencies to pyb.Pin

unix-cpy port:
- port is removed (no longer needed), along with conditional code in core

unix port:
- bump default heap size to 1MB (2MB on 64-bit systems)
- enable REPL auto-indent
- allow to build libffi from source and link against it
- add 'jni' module to interface to JNI-compliant JavaVM

windows port:
- make mpconfigport.h up-to-date with the unix port
- make unistd.h more posix compatible

stmhal port:
- use polling, not DMA, for 1 byte SPI transfers
- add 'opt' arg to pyb.main, to set mp_optimise_value
- add option to query for the current usb mode
- add support for STM32F411 Discovery Board (STM32F411E-DISCO)
- enable I & D caches for Cortex-M7
- fix single precision float printing error

cc3200 port:
- implement new Pin API
- implement new UART API
- implement new I2C API
- implement new SPI API
- implement new ADC API
- implement new WDT API
- implement new SD and RTC API plus os and time modules' extensions
- improve uniflash script and make it a bit more verbose
- increase error led blynk period to 100ms
- keep overwriting the same image on sequential updates
- improve file system check routine
- make sure to update sleep objects when registered
- reduce servers cycle time to improve FTP transfer rate
- remove unneeded loops in the FreeRTOS hooks
- server side SSL socket requires both certfile and keyfile
- don't clear the WDT special bit in the bootloader
- disable some uPy features in debug mode to help code fit
- change HeartBeat period from 5 to 4 seconds
- add mphal error to raise hardware related exceptions

esp8266 port:
- add wifi_mode() to read and set WiFi operating mode
- add wlan.isconnected() to maintain parity with other ports

docs:
- wipy: adapt ADC doc and quickref to the new API
- wipy: update I2C and UART docs to match the new API
- wipy: add pins to the I2C constructor

Lots of additions and improvements; support for STM32F2 and F7 MCUs.

py core:
- make showbc decode UNPACK_EX, and use correct range for unop/binop
- use wrapper to check self argument of builtin methods, to prevent seg faults
- remove mp_load_const_str and replace uses with inlined version
- remove mp_load_const_bytes and instead load precreated bytes object
- improve mp_import_name() debug logging
- catch case when relative import happens without active package
- fix running package submodule with -m
- add TimeoutError exception subclassed from OSError
- allow to build with debugging and bytearray but no array
- modstruct: Raise NotImplementedError for unsupported repeat specification
- REPL: Fix case where shorter names are shadowed by longer names
- prevent many extra vstr allocations by preallocating room for null byte
- improve allocation policy of qstr data (saves RAM)
- modbuiltins: Implement round() to precision
- make qstr hash size configurable, defaults to 2 bytes
- implement memoryview slice assignment, eg m1[0:3] = m2[2:5]
- viper: allow functions to take up to 4 arguments
- vipre: issue an error when compiling functions with more than 4 args
- raise SyntaxError when str hex escape sequence is malformed
- fix handling of parsing empty input so it raises an exception
- viper: compile errors now have traceback with function and filename
- REPL: don't look inside strings for unmatched brackets/quotes
- give more precise line number for compile errors (incl viper functions)
- make list += accept all arguments and add test
- makeversionhdr.py: Fallback to using docs version if no git repo

extmod:
- ubinascii: add a2b_base64 and b2a_base64 functions
- machine: implement physical memory access using /dev/mem (Linux, etc)

lib:
- readline: add emacs control chars for cursor movement (disabled by default)

drivers:
- onewire: fix ds18x20.read_temp so it works when no rom given

tools:
- update upip to 0.5.4: recognize and handle "package not found" error
- make-frozen.py: make Python2 compatibile
- pydfu.py: fix to work with old and new versions of PyUSB
- pyboard.py: fix parsing of returned error so last chr is not lost
- pyboard.py: make enter_raw_repl stricter and more reliable
- pyboard.py: speed up reading of chars by decreasing sleep period
- pyboard.py: add telnet support
- pyboard.py: make Python2 compatible

tests:
- add testcase for open(..., "a")
- adapt basics/memoryerror.py for ports with lower heap sizes
- adapt misc/features.py tests for ports without floating point
- add support for the WiPy in run-tests script (use --target to specify it)
- split out json float tests to separate files
- add test for relative import without package context
- skip parser test if "compile" builtin is not available
- use PTY when running REPL tests
- add test for pyboard SPI in slave mode, recv with no master
- test REPL emacs keys, but only if present
- always use forward slashes for paths (for Windows tests)
- fix exceptions when running cmdline tests on Windows
- Remove over-specification of startup banner

unix port:
- add O_WRONLY | O_CREAT to open call when opening file for append ("a")
- socket.getaddrinfo: accept family & socktype arguments
- socket.getaddrinfo: port is unsigned value
- modsocket: implement sendto(), recvfrom(), inet_pton()
- set MICROPY_PY_SYS_PLATFORM to "darwin" if compiled on OSX

stmhal port:
- modify dma_init() to accept init struct as an argument, making it more generic
- add config option for storage to use second flash segment (disable by default)
- add I2S support to make-pins.py
- add qstr definition for ifconfig when building for WizNet
- move HAL Cube files to f4/ subdir, keeping only those we use
- add STM32CubeF2 version 1.1.0, in hal/f2 directory
- add CMSIS device header files for STM32F2xx series
- allow DAC.write_timed to take Timer object in place of freq
- allow ADC.read_timed to take Timer object in place of freq
- check if user block device is mounted before accessing it
- put fs_user_mount pointer in root ptr section of global state (fixes crash)
- add hal and cmsis files from STM32Cube_FW_F7_V1.1.0
- add STM32F7DISC support
- factor out USRSW boot-up code and support boards with 1 LED
- factor GPIO clock enable logic into mp_hal_gpio_clock_enable
- add capability to print out info about a hard fault (disabled by default)
- fix make-pins.py to allow Port K
- add better support for UART having Tx and Rx on different ports
- add support for USART1 and conditional pins in make-pins.py
- add STM32F7 support for USB serial and storage
- enable I2C support for F7 MCUs
- enable SPI support for F7 MCUs
- fix hardfault when configured as a SPI slave
- generate modstm constants per build

cc3200 port:
- in Timer.callback() only use value param if in edge count mode
- create tools folder and add update-wipy.py script
- add deploy target and improve robustness of update-wipy.py
- enable more features to improve compatibility with stmhal
- add `Pin.name()` method
- adapt update-wipy.py timing to improve stability
- correct socket settimeout time format
- add CA, certificate and key files to the updater list
- add socket.timeout and socket.error exceptions
- raise an exception if trying to scan for networks in AP mode
- optimize check for WLAN AP mode
- set WLAN date/time via the rtc.datetime method()
- add modussl, ssl sockets subclassed from normal sockets
- time.sleep() now receives seconds, like CPython
- fix socket recv and recvfrom return value type
- enable base64 methods from modubinascii
- increment interrupt stack size from 2K to 3K
- create /flash/sys and /flash/lib directories while booting
- translate simplelink's socket error numbers to POSIX values
- use alternative HAL_Delay also when interrupts are disabled
- correct udelay us to ticks calculation
- increment telnet Tx retry delay on every try
- add struct weak link for ustruct
- set simplelink time and date when enabling WLAN
- refactor and clean-up socket closing code
- implement new OTA mechanism with 2 firmware update slots
- create /flash/cert folder if it doesn't exist
- make socket stream methods return POSIX error codes
- add socket.sendall() (aliases to send())
- rename pins from GPIO to just GP
- add socket.makefile()
- switch to 1 byte hash for QSTRs
- on ssl.read() or ssl.readall() ignore ssl layer closed error
- append last 2 bytes of the MAC address to the default SSID
- make I2C and SPI API the same as in stmhal
- add nic.iwconfig() to set/get WLAN configuration
- improve support for WEP security
- enable bootloader safe boot on latest firmware
- fix bug in ffconf regarding '/flash' string length
- add script to program the WiPy via UniFlash (windows only...)
- add factory smoke test as part of the tools
- speed up file system checking during start-up
- on the first boot, always make AP ssid='wipy-wlan'
- make ADC API compatible with the pyboard

esp8266 port:
- move scan() from esp module to network
- update the README.md to reflect what works
- move status() from esp module to network
- make pyb.RTC a type, and pyb.RTC() constructs an RTC object
- allow to easily override programming baudrate

docs:
- add more documentation for the CC3200 in the pyb module
- add "reference" directory for putting docs about the language
- add reference for Thumb2 inline assembler
- make index link point to "index.html" irrespective of port
- fix duplicate label error for network.WLAN
- update safe boot comments to match actual behaviour
- update pyb.Accel doc to reflect changes and explain filtered_xyz
- correct nic.ifconfig() quickref example
- add i2c keywork arguments only indication

Unix binary gets tab completion and builtin upip, and more.

py core:
- allow to compile without needing git to extract version
- conform to CPython's way of printing nan/inf with padding
- wrap qstr defs in quotes to protect from C preprocessor
- add stack check to mp_iternext to catch nested iterators
- implement implicit cast to obj for viper load/store index/value
- implement native multiply operation in viper emitter
- expose KeyboardInterrupt in builtins module
- fallback to stack alloca for Python-stack if heap alloc fails
- support unicode (utf-8 encoded) identifiers in Python source
- implement second arg for math.log (optional value for base)
- support mpz bignums in divmod builtin

extmod:
- add ubinascii.unhexlify
- swap address and descriptor args in uctypes constructor

lib:
- fix some issues with dates prior to 1 Mar 2000
- implemente delete key in readline

tools:
- pyboard.py: allow pyboard constructor to take a baudrate parameter
- pyboard.py: change logic for when raw ">" prompt is parsed
- add codestats.sh to compute code statistics such as size, speed

unix port:
- add option to use uPy readline and enable by default (adds tab completion)
- include upip as frozen module within standard uPy executable; standard
  way to use is: micropython -m upip install <module>
- allow to cat a script into stdin from the command line
- make micropython -m <module> work for frozen modules

windows port:
- implement mp_hal_xxx functions and enable uPy readline

stmhal port:
- raise error if disk is full when writing a file
- implement sys.stdin.buffer, sys.stdout.buffer for raw byte mode
- remove all PYBVxx defines and use general config vars instead
- add support for UART5 if MCU has it
- fix slow SPI DMA transfers by removing wfi from DMA wait loop
- break immediately from USB CDC busy wait loop if IRQs disabled
- make I2C transfers use DMA when possible (when IRQs are enabled)

cc3200 port:
- add os.rename()
- add Timer module
- add uhashlib with SHA1 and SHA256
- add ubinascii module
- implement full set of wake-on-WLAN features
- remove NIC abstraction layer
- improve WDT
- make peripheral API more similar to stmhal's
- improve reliability of ftp and telnet servers
- add antenna selection feature to WLAN
- add sendbreak method to UART

esp8266 port:
- add uos module
- allow to set CPU frequency to 160MHz using pyb.freq
- add pyb.ADC class
- to esp module add: mac, phy_mode, sleep_type, deepsleep, flash_id
- update SDK to version 1.1.0 (MIT licensed)
- fix lost chars when transfering large amounts of data over UART
- add skeleton "network" module with bare WLAN() constructor
- add WLAN.connect/disconnect functions
- change esp_scan to keep the current WiFi operating mode

docs:
- document esp module
- allow to generate separate docs for each port (using ..only directive)
- add initial docs for the WiPy

Tab autocompletion, and various improvements and bug fixes.

py core:
- add attrtuple for space efficient tuples with attr access
- add sys.implementation, with uPy name and version number
- fix printing of "inf" and "nan" values
- native: fix stack adjustment when erroring on binary op
- mpz: fix bug with shl not truncating zero digits correctly
- modify "with" implementation so it doesn't use any heap
- add sys.exc_info()
- implement conversion of bignum to bytes
- implement struct.pack with 'q' and 'Q' args on 32-bit archs
- replace py-version.sh with makeversiohdr.py, written in Python
- implement tab autocompletion for REPL
- rename struct module to ustruct
- add NotImplemented builtin constant
- handle user instance hash based on Python adhoc rules
- fix naming of function arguments when function is a closure
- fix printing of complex numbers with nan/inf

extmod:
- add machine module, with mem8, mem16, mem32 objects

lib:
- move common mod_network_* functions to lib/netutils
- move common time functions to lib/timeutils

tools:
- pyboard.py: add "--follow" option to wait for output indefinitely
- add script to install "upip" package manager

tests:
- add more viper tests, including for ViperTypeError
- coverage at 94%

unix port:
- modffi: support passing float/double args
- add special function to coverage build to improve coverage
- print unhandled exceptions to stderr

stmhal port:
- implement os.uname()
- reset timer counter to zero after changing auto reload
- properly disable unhandled timer interrupts
- automatically reenable IRQs when code drops to the USB REPL
- allow to configure UART pins completely via mpconfigboard.h
- make raw REPL work with event-driven version of pyexec
- add rtc.calibration() method to get/set RTC fine-tuning value
- add os.rename()
- add readinto() and readlines() methods to sys.stdin and pyb.USB_VCP

cc3200 port:
- add WiPy specific info to README.md
- fix byte order in MAKE_SOCKADDR and UNPACK_SOCKADDR
- select NIC when the socket is created
- add delays to allow ftp and telnet servers to start/stop
- make telnet login work with Tera Term
- implement os.uname()
- make WLAN scan results a list of attrtuples
- make WLAN.isconnected() also work in AP mode
- implement Sleep.wake_reason()
- make WLAN.ifconfig() return an attrtuple
- enable MICROPY_MODULE_WEAK_LINKS

esp8266 port:
- export station status() constants
- add esp.socket class, with ESP-style socket functionality
- add raw REPL support and working soft reset
- fix garbage collector by hard-coding stack end address
- add socket.onsent() callback support
- add support for frozen modules
- implement time functions
- add utime and pyb.RTC
- add module weak links

docs:
- document pyb.stop, pyb.standby, pyb.RTC.wakeup
- document USB_VCP read* and write methods

Improved native codegen, better printf, support for F401 and F411 MCUs.

py core:
- implement delete for property and descriptors
- add option to disable "enumerate" and "reversed" builtins
- can call functions with *args in native emitter
- implement full function arg passing for native emitter
- combine load_attr and store_attr internal type methods into one
- fix formatting of floating point numbers near 1.0
- support assignment of bytes to bytearray slices
- overhaul and simplify printf/pfenv mechanism
- fix builtin ord so that it can handle bytes values >= 0x80
- inlinethumb: add support for core floating point instructions
- make viper code generator raise ViperTypeError on error

lib:
- string0.c now in lib/libc/ (was in stmhal/)
- fatfs code size reduced (by 768 bytes on Thumb2 archs)

tests:
- more tests for builtins
- tests for lexer
- coverage increased to 93%

stmhal:
- make LED object print LED(x) for consistency with constructor
- in USB HID driver, make polling interval configurable
- allow sending CAN messages with timeout=0
- add support for sending and receiving CAN RTR messages
- make board parameters more configurable (HSE PLL, LED4, TIMs, etc)
- add support for F401 and F411 MCUs
- add support for Espruino Pico board
- make raw REPL mode 8-bit clean

cc3200 port:
- enable pull-ups for stdio UART pins
- enable long filename support in fatfs
- add WLAN.config_ip(), to assign a static IP
- add IPPROTO_SEC so secure sockets can be made

tools:
- make pyboard.py 8-bit clean, so it works with unicode chars

docs:
- document pyb.main() function

Stackless support, new 16-bit PIC port.

py core:
- builtin round() accepts second arg
- add more special methods: __pos__, __neg__, __invert__
- support for stackless Python calls in VM, strict and non-strict
- support for object representation that suits 16-bit archs
- implement closures in native code emitter
- implement str.splitlines() method

lib:
- fatfs library upgraded to R0.11 (fixes bugs with unlink)

pic16bit port:
- new port to 16-bit PIC (reference MCU is dsPIC33J256GP506)
- heap is 4600 bytes
- implement basic pyb module with delay
- implement basic LED and Switch classes

docs:
- initial docs for micropython module
- additional example for Timer callback usage
- document instantiating struct objects in uctypes

More Python features, reduced code size, coverage testing at 91%.

py core:
- add builtin setattr function
- optimise exceptions for out-of-memory scenario
- add some special methods: __mul__, __floordiv__, __truediv__
- implement array slice assignment
- add support for start/stop/step attrs in range object
- make builtin abs work with bools and bignums
- add basic implementation of collections.OrderedDict
- add support for a function's __name__
- refactor compiler code to reduce code size by up to 2k
- support for descriptors __get__ and __set__

inline Thumb2 assembler:
- more robust syntax checking
- general bug fixes
- better error messages
- add "it" instructions
- add bl, bx instructions
- add bcc_n, bcc_w instructions

extmod:
- modure: bug fixes for groups
- modure: add named classes

lib:
- libm: add erf, erfc, lgamma, tgamma

drivers:
- add onewire driver in pure Python
- add ds18x20 temp sensor driver, using onewire
- cc3100 driver upgraded to v1.1.0

tests:
- lots of new tests, including many for SyntaxError
- automated covage testing using coveralls, at 91% coverage

unix port:
- support for readline history saving to file

stmhal port:
- usbdev code cleanup
- add Python-configurable USB HID mode
- add CDC only USB option
- improve USB descriptors (untested on Windows and Mac)
- add UART.sendbreak() method to send break condition
- add support for CAN rx callbacks
- raise error if UART can't do requested baudrate within 5%
- fix timing init when callback is passed as argument to init
- add support for quadrature encoder mode in TimerChannel
- fix ADC.read_timed so buffer store respects element size
- add RTC.wakeup method to set wakeup timer (preliminary)
- add compile-time config option for RTC to use LSE or LSI
- bug fix related to unhandled channel interrupts
- improved support for stop and standby mode
- expose all PYBv1.0 pins, including SD and USB pins
- optimise ADC.read_timed so it can sample at up to 750kHz
- make pybstdio code usable by other ports

cc3200 port:
- add I2C module
- add ADC module
- add SD module
- support for connecting to WEP secured networks
- add WDT support
- add low power support
- add SPi module

esp8266 port:
- add basic pyb.Pin class

miscellaneous:
- add list of Kickstarter backers in ACKNOWLEDGEMENTS file

size difference in bytes to previous version (a negative value means
binary is smaller in this version):
- bare-arm: -2448
- minimal: -3028
- unix: +574
- stmhal: +7996
- cc3200: -2984
- teensy: -10560
- esp8266: -936
- qemu-arm: -844

Bug fixes, CC3200 port, improved inline assembler

py core:
- big-int bug fixes
- support for floats in struct module
- vstr no longer null-terminates buff by default
- properly handle CR/LF in triple-quoted string
- list.sort now has O(log(N)) stack usage
- parse big-int/float constants directly in parser
- allow to subclass native buffer objects
- reduce stack size of VM by 8 bytes on stmhal, 16 on x86
- add ldrex, strex, push, pop, sdiv, udiv, clz, rbit to inline assembler
- make inline assembler report line numbers on error

extmod:
- uzlib: raw deflate decoding support

unix port:
- add "coverage" makefile target for coverage testing

stmhal port:
- bug fixes in ADCAll object
- bug fix in timer.deinit

esp8266 port:
- add esp module
- add connect, disconnect, status functions

cc3200 port:
- new port to the CC3200 launchxl board

Internal changes, RAM and ROM reductions, new minimal port

py core:
- lots of small optimisations, cleanups and code size reduction
- move away from Plan 9 headers to traditional guarded ones
- improved and optimised float to int conversion
- fix right-shifting edge cases in mpz
- namedtuple: use sequence of strings for init
- namedtuple: allow keyword arguments in constructor
- ability to issue compile/runtime warnings
- str.format now has kwargs support
- put all global state togther in a state structure
- optimisation to cache map lookup results in bytecode
- fix handling of "0" in some mpz functions
- implement equality check for all types
- add qstr cfg capability
- can now configure qstr len storage; defaults to using 1 byte
- allow code to compile with lots more warnings enabled
- add LOAD_CONST_OBJ bytecode, to directly load Python objects
- never intern data of large str/bytes objects
- fix handling of default except in compiler
- add extra pass to bytecode compiler to compute stack size
- implement very simple frozen modules support
- implement __reversed__ slot
- implement proper re-raising in native codegen's finally handler

lib:
- move readline code from stmhal to lib/mp-readline/
- readline refactored to support event-driven usage
- add frexp and modf to libm

minimal port:
- new port, intended to represent minimal working code

stmhal port:
- collect root pointers together; improves GC speed
- add MICROPY_HW_USB_VBUS_DETECT_PIN option
- add MICROPY_HW_USB_OTG_ID_PIN option
- add support for FEZ Cerb40 II board
- bug fixes in network module and usocket.accept, setsockopt

qemu-arm port:
- enable GC and native code-gen
- add working tests
- get tests running under Travis CI

esp8266 port:
- use dedicated heap allocated as static array
- implement task-based, event-driven interface with UART
- implement pyb.hard_reset()

Feature additions to core, unix and stmhal; general improvements.

py core:
- implement +, +=, .extend for bytarray and array objs
- add mem_info, qstr_info to micropython module
- bytes/bytearray/array can be init'd by buffer protocol objs
- optimised lexer by exposing lexer type; gives ROM savings
- add sys.print_exception
- allow builtins to be overridden
- fixed all semantic issues with range optimisation
- compiler gives proper SyntaxError exceptions for bad global/nonlocal
- reduce VM exception stack size by 1 machine word per exception
- make bytes objs work with more str methods
- refactor and make mp_bytecode_print and friends more useful
- start transition to guarded includes
- lots of code cleanup
- some ROM savings

extmod:
- add ubinascii module, with hexlify

unix port:
- add _os.unlink, _os.system functions
- 64-bit clean in ffi module
- time module renamed to utime

stmhal port:
- add USB_VCP.setinterrupt method, to disable CTRL-C
- make pyb.[u]delay work when irqs are disabled
- overhaul of internal network driver interface
- bug fixes to CC3K and WIZNET5K network drivers
- use DMA for SPI transfers (only if irqs enabled)
- allow SPI.init to specify prescaler directly
- enhance pyb.freq to configure bus frequencies
- add more math functions (acosh, asinh, atanh, tan)
- add execfile function
- upgrade to latest FatFs driver (now in lib/)
- add ability to mount custom block device

esp8266 port:
- put more rodata in irom section
- add README.md

docs:
- basic docs for uhashlib, ubinascii, ure, uzlib
- links to LCD and AMP skin schematics
- general improvements

Port to ESP8266, add uhashlib, improved CAN driver.

py core:
- support more ops for bytes/bytarray
- support __hash__ for user-defined types
- support for float/double arrays in array module
- shorter error messages for TERSE message option
- add seek via ioctl to stream protocol

extmod:
- add uhashlib with sha256

unix port:
- heapsize can take w specifier for word adjustment

stmhal port:
- CAN init now takes sjw, bs1, bs2 args
- add CAN filter management
- fix HAL error raising bug

esp8266 port:
- new port to ESP8266 wifi chip

docs:
- minor additions

Improved documentation, and other small changes.

py core:
- add builtin round function
- gc.enable/disable still allows manual GC (as per CPython)
- fix builtin callable for user-defined types
- fix bug for right shift of small int by large amount

unix port:
- add "fast" version
- improve uctypes, including sizeof function

stmhal port:
- support for extended CAN frames
- USB_VCP works with select
- experimental support for RTS/CTS in UART
- make UART bits count number of data bits, not incl parity
- pyb.freq now allows 8MHz and 16MHz

docs:
- revamp and merge all inline docs into Sphinx framework
- add a few more tutorials

RAM savings, memoryview, quick-ref and more.

Improvements to core:
- make better use of bytecode coding space
- about 10% RAM savings in bytecode
- add uheapq module
- add memoryview builtin
- add compile builtin
- support in VM for KeyboardInterrupt
- fix integer modulo with negative arguments
- small GC fixes
- add 2nd arg to readinto

New features in unix port:
- CTRL-C raises KeyboardInterrupt
- heapsize option takes K and M
- -m option to execute library module

stmhal improvements:
- make MMA_INT/PB2 pin available
- add pyb.hard_reset()
- cc3k recv improments
- all HAL errors now raise OSError with POSIX error code
- USB config improved for windows (CDC on Windows 10 without driver)
- use different USB PID when in CDC+HID mode (so HID works in Windows)
- boot.py and main.py use \r\n for newlines
- change SPI phase from 1,2 to 0,1 to match industry conventions
- allow DAC object to be init'd from pin
- improved raw REPL control codes
- improved pyboard.py script

docs:
- add quick reference page with pinout

Add regex and CAN, improve UART, and more.

py core:
- add basic regex support using re1.5 library
- replace zlibd with uzlib
- compiler returns proper exception on SyntaxError
- proper context saving for eval/exec
- use mp_[u]int_t in most places instead of [u]int
- better ARM support in native emitter
- autodetect machine endianness
- better big endian support
- memory errors from locked gc can be reported
- more robust lexer when out of memory
- rename modules to begin with u-, and add module weak links
- more native binops in viper emitter
- native pointers with load+store in viper
- fix GC realloc so that chunks are shrunk correctly
- compiler optimisations for constant if/while conds
- add kwargs for builtin open() and FileIO
- enable unicode on windows

stmhal port:
- add basic CAN bus support
- overhaul UART class to use read/write
- add NRF24L01 driver (in pure Python)
- pyb.freq can change SYSCLK
- add pyb.stop and pyb.standby
- can set Timer freq using float
- Timer supports complementary channel and deadtime
- add retry for SD card init

Network support in stmhal, and improved viper compiler.

Changes in core:
- tidy up native emitter and assemblers
- viper can compiler more binary ops
- viper supports casting (int, ptr8, ptr16)
- viper can compile native stores (eg p[1] = 42)
- remove IOError (use OSError instead)

stmhal port:
- fix OSX mass storage issue, so pyboard can be left plugged in
- add network and usocket modules with CC3000 and WIZnet5k support
  (disabled by default)
- improved percent option in timer PWM
- add pyb.elapsed_millis, pyb.elapsed_micros
- internal flash is labelled as "pybflash" on creation
- don't init NSS pin when initialising SPI bus with NSS_SOFT mode

Changes in core:
- bytecode prelude uses less RAM
- free non-interned strings earlier
- add builtins module
- add ujson module with dumps and loads
- mpz div changed so that mpz is more efficient
- some compiler optimisations
- some simplifications of the code
- bug fix memcpy -> memmove
- changed most instances of int/uint to mp_int_t/mp_uint_t
- added ioctl method to stream protocol
- divmod, % and // support for floating-point numbers

Native emitter enhancements:
- bug fixes
- support for delete name and global
- support for end finally
- x86 support
- x86-64 can use extended regs

unix port:
- MIPS compilation support

stmhal port:
- add generic select module
- ability to select/poll on UART objects
- proper SDHC support (cards > 4gb now work)
- enhanced timer support (PWM, OC, IC)
- big fix with miss-aligned stack pointer
- more math functions implemented

Added drivers subdirectory with WIZNet5200 support
(disabled by default).

Added docs subdirectory and moved to Sphinx docs.

Improved teensy support.

Bug fixes, viper improvements, and more

New features in core:
- min and max accept key= argument
- accepts user defined ==, >, <=, >=
- native support for ARM (non thumb)
- cut RAM and ROM usage of zlibd
- significant GC allocation speed up

Viper improvements:
- type annotations
- store to global
- call functions with native types
- raise exceptions

Bug fixes to core:
- fix multiplication of a sequence by negative number
- GC bug fix where native code was being collected
- int(b'1234') now works
- can now make strings longer than 64k

unix port:
- modtermios for unix
- make install for unix

stmhal port:
- reduced code size by 35k
- put some code into first 16k block
- in safe mode SD card is still presented as MSD
- SD card init fixes; should be more reliable
- added time.mktime; enhanced time.localtime
- new Pin functions: mode, pull, af
- nestable enable_irq/disable_irq
- added pyb.micros()
- added USB_VCP.any()
- STM32F4DISC accel support via staccel.py script

v1.3: New features and many bug fixes.

New features include:
- file.flush, os.stat
- unicode enabled by default on unix and stmhal ports
- print function accepts file= argument
- I2C object allows for 16-bit mem addr
- emergency exception buffer for improved exception traceback
- USB_VCP object
- 0:/ and 1:/ changed to /flash and /sd
- improved Pin object
- can set pin alternate function from Python
- builtin reversed, can len() and subscr range objects
- added moductypes
- added modzlibd for DEFLATE decompression

Code improvements include:
- more efficient line-number to bytecode mapping
- new STM HAL driver v1.3.0

Bug fixes include:
- mpz (bignum) fixes
- accel startup improved
- important bug fix in GC

v1.2: Unicode support (disabled by default); bug fixes and minor features added.