Implemented support for `in` and `not in` operators.
Merge remote-tracking branch 'upstream/master' into containment

Conflicts:
	py/runtime.c
Merge remote-tracking branch 'upstream/master' into containment
Fixed the merge so it worked and compiled and stuff
Add combined image to GitHub front page README.md
made DEBUG control CFLAGS in Makefiles oter than stm as well.
Add "buffer management" and "shrink" API calls to vstr.

vstr is initially intended to deal with arbitrary-length strings. By
providing a bit lower-level API calls, it will be also useful to deal
with arbitrary-length I/O buffers (the difference from strings is that
buffers are filled from "outside", via I/O).

Another issue, especially aggravated by I/O buffer use, is alloc size
vs actual size length. If allocated 1Mb for buffer, but actually
read 1 byte, we don't want to keep rest of 1Mb be locked by this I/O
result, but rather return it to heap ASAP ("shrink" buffer before passing
it to qstr_from_str_take()).
Add generic impl of stream .readall() method. Use one for unix io.FileIO.
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master' into containment
Add missing ADC driver

* Add missing ADC driver from STM32F4xx_StdPeriph_Lib_V1.3.0
Implement initial ADC support

* Add simple ADC driver, with support for ADC1 and all channels.
* Export MicroPython ADC object with read_channel function.
* Add stm32f4xx_adc.c and adc.c to Makefile.
Add ADC support for internal TEMP/VBAT/VREF

* Add ADC support for reading internal temperature sensor.
* Add ADC support for reading internal VREF/VBAT monitor.
Refactor exception objects to have better impl of Python-side interface.

This implements internal args tuple of arguments, while still keeping
object useful for reporting C-side errors.

Further elaboration is needed.
Tidy up.
Merge pull request #142 from chipaca/containment

Implemented support for `in` and `not in` operators.
Merge pull request #161 from pfalcon/exc-more-pythonic

Move towards Python-compliant interface of exceptions
Merge pull request #173 from pfalcon/file-readall

Generic implementation if stream readall() method, immediately reused in unix io.FileIO implementation
Merge pull request #175 from iabdalkader/master

Add missing ADC driver
Merge pull request #163 from Metallicow/README-branch

Add combined image to GitHub front page README.md