made DEBUG control CFLAGS in Makefiles other than stm as well.

Thanks to Dave Hylands for this.

Add combined image to GitHub front page README.md

Add missing ADC driver

Generic implementation if stream readall() method, immediately reused in unix io.FileIO implementation

Move towards Python-compliant interface of exceptions

Implemented support for `in` and `not in` operators.

added zip()

So far, don't work for strings as expected.

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

Further elaboration is needed.

This is useful because tuple is closest analog of C static array.

* Add ADC support for reading internal temperature sensor.
* Add ADC support for reading internal VREF/VBAT monitor.

* 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 missing ADC driver from STM32F4xx_StdPeriph_Lib_V1.3.0

Conflicts:
	py/builtin.c
	py/builtin.h
	py/runtime.c

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()).

By dispatching to long int methods.

Made sorted() raise an exception instead of aborting when given no arguments; moved around some things in objfun.c as a consequence

Added public domain implementations of strchr and strstr.

Initialize is_kw for dynamically allocated mp_obj_fun_native_t ojects.

This should fix issue #171

Also new vector_log png with alpha

Implement a basic str.find; fixes #67