Updated teensy to build.

Refactored some stmhal files which are shared with teensy.
gc: More verbose debugging

Add more DEBUG_printf statements to trace gc behaviour
gc: Keep debug statements at beginning of scope where possible
gc: Turn off debugging info again
Add MICROPY_HW_MICRO_NAME to boards config
Add missing “assert.h” file header inclusion from “nlr.h”
Prefix ARRAY_SIZE with micropython prefix MP_
bench: Add test for function call overhead.

For a trivial operation, calling a function is 5 times slower than doing
operation inline.
bench: Add tests for constructing various containers from iterator.

Both "bound" (like, length known) and "unbound" (length unknown) are tested.
All of list, tuple, bytes, bytesarray offer approximately the same
performance, with "unbound" case being 30 times slower.
bench: Add test for map() vs inplace operations in array-likes.

map() is 5 times slower. That's mostly because of inefficiency of creating
containers from iterables of unknown length (like map()).
bench: Three ways to process a byte buffer.
Added hexfile target
Merge pull request #707 from eblot/master-v1.1.1-build-fixes

Fix missing declaration of assert()
Replace ARRAY_SIZE with MP_ARRAY_SIZE
Merge pull request #697 from stinos/gc-debug

gc: More verbose debugging
py: Separate MICROPY_PY_BUILTINS_COMPLEX from MICROPY_PY_BUILTINS_FLOAT.

One thing is wanting to do 1 / 2 and get something else but 0, and quite
another - doing rocket science ;-).
tests/float/: Skip tests if "math" module is not available.
unix: Allow to override compiler warning options without touching the rest.

Some people want to enable even more warnings. Let them do it without putting
burden on everyone. Some people vice versa think that current settings should
be relaxed. In this regard, -Werror is the most problematic, it disallows to
use #warning directive, and disallows to pass configuration settings on make
command lines. Again, until decided how to deal with these globally, allow to
work around these problems locally.
unix: Group CFLAGS related stuff together.
unix: Refactor order file munging fo MacOSX.
unix: Add CFLAGS_EXTRA & LDFLAGS_EXTRA for command line usage.

The idea is that it should be possible to pass any additional params for
experimentation without need to patch sources (and without need to deviate
from or repeat baseline options).