stmhal: Change cc3k.recv to only make 1 call to underlying recv().

Also make cc3k.send and cc3k.recv independent functions (not wrapped by
stream write/read).  Also make wiznet5k.recv more memory efficient.

This might address issue #920.
Add pyb.hard_reset, and make sys.exit() or raise SystemExit do a soft reset.
stmhal: Don't return SystemExit value from parse_compile_execute.

There is no need, since we don't (currently) use the value.
Fixed TIM2_CH1 definition.

TIM2_CH1_ETR is really bundling 2 functions to the same pin:
TIM2_CH1 (where its used as a channel)
TIM2_ETR (where iss used as an external trigger).

I fixed most of these a while back, but it looks like I missed this one.
stmhal: Add MMA_INT/PB2 to available pins on PYBV10.

This allows you to register ExtInt on the MMA interrupt pin.
py: Remove unused and unneeded SystemError exception.

It's purpose is for internal errors that are not catastrophic (ie not as
bad as RuntimeError).  Since we don't use it, we don't need it.
Add pydfu.py to the micropython tree. Use dfu_util bgy default

You can do:

make USE_PYDFU=1 deploy

to use pydfu.py
tools, pydfu: Some fixes to support Python 3.
py: Fix smallint modulo with negative arguments.

Addresses issue #927.
extmod: Add uheapq module.
py: Clean up edge cases of malloc/realloc/free.
py: Use MP_OBJ_NULL instead of NULL in a few places.
py: Add builtin memoryview object (mostly using array code).
py: Properly free string parse-node; add assertion to gc_free.
stmhal: Use OSError with POSIX error code for HAL errors.

Addresses issue #921.
stream: Add optional 2nd "length" arg to .readinto() - extension to CPython.

While extension to file.readinto() definition of CPython, the additional arg
is similar to what in CPython available in socket.recv_into().
Add pyb.soft_reset() and pyb.hard_reset() commands.
Creating new board nustat10

Creating new board with custom pins and 24MHz crystal
Makefile moved
Changed pin description

Pin names for nustat10