Merge tag 'v1.9.1'2.0.0-alpha.0

Fixes for stmhal USB mass storage, lwIP bindings and VFS regressions

This release provides an important fix for the USB mass storage device in
the stmhal port by implementing the SCSI SYNCHRONIZE_CACHE command, which
is now require by some Operating Systems.  There are also fixes for the
lwIP bindings to improve non-blocking sockets and error codes.  The VFS has
some regressions fixed including the ability to statvfs the root.

All changes are listed below.

py core:
- modbuiltins: add core-provided version of input() function
- objstr: catch case of negative "maxsplit" arg to str.rsplit()
- persistentcode: allow to compile with complex numbers disabled
- objstr: allow to compile with obj-repr D, and unicode disabled
- modsys: allow to compile with obj-repr D and PY_ATTRTUPLE disabled
- provide mp_decode_uint_skip() to help reduce stack usage
- makeqstrdefs.py: make script run correctly with Python 2.6
- objstringio: if created from immutable object, follow copy on write policy

extmod:
- modlwip: connect: for non-blocking mode, return EINPROGRESS
- modlwip: fix error codes for duplicate calls to connect()
- modlwip: accept: fix error code for non-blocking mode
- vfs: allow to statvfs the root directory
- vfs: allow "buffering" and "encoding" args to VFS's open()
- modframebuf: fix signed/unsigned comparison pendantic warning

lib:
- libm: use isfinite instead of finitef, for C99 compatibility
- utils/interrupt_char: remove support for KBD_EXCEPTION disabled

tests:
- basics/string_rsplit: add tests for negative "maxsplit" argument
- float: convert "sys.exit()" to "raise SystemExit"
- float/builtin_float_minmax: PEP8 fixes
- basics: convert "sys.exit()" to "raise SystemExit"
- convert remaining "sys.exit()" to "raise SystemExit"

unix port:
- convert to use core-provided version of built-in import()
- Makefile: replace references to make with $(MAKE)

windows port:
- convert to use core-provided version of built-in import()

qemu-arm port:
- Makefile: adjust object-file lists to get correct dependencies
- enable micropython.mem_*() functions to allow more tests

stmhal port:
- boards: enable DAC for NUCLEO_F767ZI board
- add support for NUCLEO_F446RE board
- pass USB handler as parameter to allow more than one USB handler
- usb: use local USB handler variable in Start-of-Frame handler
- usb: make state for USB device private to top-level USB driver
- usbdev: for MSC implement SCSI SYNCHRONIZE_CACHE command
- convert from using stmhal's input() to core provided version

cc3200 port:
- convert from using stmhal's input() to core provided version

teensy port:
- convert from using stmhal's input() to core provided version

esp8266 port:
- Makefile: replace references to make with $(MAKE)
- Makefile: add clean-modules target
- convert from using stmhal's input() to core provided version

zephyr port:
- modusocket: getaddrinfo: Fix mp_obj_len() usage
- define MICROPY_PY_SYS_PLATFORM (to "zephyr")
- machine_pin: use native Zephyr types for Zephyr API calls

docs:
- machine.Pin: remove out_value() method
- machine.Pin: add on() and off() methods
- esp8266: consistently replace Pin.high/low methods with .on/off
- esp8266/quickref: polish Pin.on()/off() examples
- network: move confusingly-named cc3200 Server class to its reference
- uos: deconditionalize, remove minor port-specific details
- uos: move cc3200 port legacy VFS mounting functions to its ref doc
- machine: sort machine classes in logical order, not alphabetically
- network: first step to describe standard network class interface

examples:
- embedding: use core-provided KeyboardInterrupt object

3 files changed, 28 insertions, 20 deletions

diff --git a/docs/esp8266/tutorial/intro.rst b/docs/esp8266/tutorial/intro.rst
index fe824cfff..67ed0ba67 100644
--- a/docs/esp8266/tutorial/intro.rst
+++ b/docs/esp8266/tutorial/intro.rst
@@ -20,9 +20,12 @@ characteristic of a board is how much flash it has, how the GPIO pins are
 connected to the outside world, and whether it includes a built-in USB-serial
 convertor to make the UART available to your PC.
 
-The minimum requirement for flash size is 512k.  A board with this amount of
-flash will not have room for a filesystem, but otherwise is fully functional.
-If your board has 1Mbyte or more of flash then it will support a filesystem.
+The minimum requirement for flash size is 1Mbyte. There is also a special
+build for boards with 512KB, but it is highly limited comparing to the
+normal build: there is no support for filesystem, and thus features which
+depend on it won't work (WebREPL, upip, etc.). As such, 512KB build will
+be more interesting for users who build from source and fine-tune parameters
+for their particular application.
 
 Names of pins will be given in this tutorial using the chip names (eg GPIO0)
 and it should be straightforward to find which pin this corresponds to on your
@@ -72,15 +75,17 @@ For best results it is recommended to first erase the entire flash of your
 device before putting on new MicroPython firmware.
 
 Currently we only support esptool.py to copy across the firmware.  You can find
-this tool here: `<https://github.com/themadinventor/esptool/>`__, or install it
-using pip (at least version 1.2.1 is required)::
+this tool here: `<https://github.com/espressif/esptool/>`__, or install it
+using pip::
 
     pip install esptool
 
-It requires Python 2.7, so you may need to use ``pip2`` instead of ``pip`` in
-the command above.  Any other
-flashing program should work, so feel free to try them out, or refer to the
-documentation for your board to see its recommendations.
+Versions starting with 1.3 support both Python 2.7 and Python 3.4 (or newer).
+An older version (at least 1.2.1 is needed) works fine but will require Python
+2.7.
+
+Any other flashing program should work, so feel free to try them out or refer
+to the documentation for your board to see its recommendations.
 
 Using esptool.py you can erase the flash with the command::
 
@@ -88,7 +93,7 @@ Using esptool.py you can erase the flash with the command::
 
 And then deploy the new firmware using::
 
-    esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=detect 0 esp8266-2016-05-03-v1.8.bin
+    esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=detect 0 esp8266-20170108-v1.8.7.bin
 
 You might need to change the "port" setting to something else relevant for your
 PC.  You may also need to reduce the baudrate if you get errors when flashing
@@ -99,7 +104,7 @@ For some boards with a particular FlashROM configuration (e.g. some variants of
 a NodeMCU board) you may need to use the following command to deploy
 the firmware (note the ``-fm dio`` option)::
 
-    esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=detect -fm dio 0 esp8266-2016-05-03-v1.8.bin
+    esptool.py --port /dev/ttyUSB0 --baud 460800 write_flash --flash_size=detect -fm dio 0 esp8266-20170108-v1.8.7.bin
 
 If the above commands run without error then MicroPython should be installed on
 your board!
@@ -158,7 +163,9 @@ after it, here are troubleshooting recommendations:
   esptool.py, which had a different programming algorithm::
     pip install esptool==1.0.1
   This version doesn't support ``--flash_size=detect`` option, so you will
-  need to specify FlashROM size explicitly (in megabits).
+  need to specify FlashROM size explicitly (in megabits). It also requires
+  Python 2.7, so you may need to use ``pip2`` instead of ``pip`` in the
+  command above.
 
 * The ``--flash_size`` option in the commands above is mandatory. Omitting
   it will lead to a corrupted firmware.
@@ -179,7 +186,7 @@ after it, here are troubleshooting recommendations:
   application in the ESP8266 community.
 
 * If you still experience problems with even flashing the firmware, please
-  refer to esptool.py project page, https://github.com/themadinventor/esptool
+  refer to esptool.py project page, https://github.com/espressif/esptool
   for additional documentation and bug tracker where you can report problems.
 
 * If you are able to flash firmware, but ``--verify`` option or
diff --git a/docs/esp8266/tutorial/pins.rst b/docs/esp8266/tutorial/pins.rst
index a44f40d3a..cd45c83cd 100644
--- a/docs/esp8266/tutorial/pins.rst
+++ b/docs/esp8266/tutorial/pins.rst
@@ -35,8 +35,8 @@ Then set its value using::
 
 Or::
 
-    >>> pin.low()
-    >>> pin.high()
+    >>> pin.off()
+    >>> pin.on()
 
 External interrupts
 -------------------
diff --git a/docs/esp8266/tutorial/repl.rst b/docs/esp8266/tutorial/repl.rst
index 1922da128..ba64fcccb 100644
--- a/docs/esp8266/tutorial/repl.rst
+++ b/docs/esp8266/tutorial/repl.rst
@@ -24,7 +24,7 @@ terminal programs that will work, so pick your favourite!
 
 For example, on Linux you can try running::
 
-    picocom /dev/ttyUSB0
+    picocom /dev/ttyUSB0 -b115200
 
 Once you have made the connection over the serial port you can test if it is
 working by hitting enter a few times.  You should see the Python REPL prompt,
@@ -101,11 +101,12 @@ turn it on and off using the following code::
 
     >>> import machine
     >>> pin = machine.Pin(2, machine.Pin.OUT)
-    >>> pin.high()
-    >>> pin.low()
+    >>> pin.on()
+    >>> pin.off()
 
-Note that ``high`` might turn the LED off and ``low`` might turn it on (or vice
-versa), depending on how the LED is wired on your board.
+Note that ``on`` method of a Pin might turn the LED off and ``off`` might
+turn it on (or vice versa), depending on how the LED is wired on your board.
+To resolve this, machine.Signal class is provided.
 
 Line editing
 ~~~~~~~~~~~~