created SDdatalogger example
deleted garbage
showbc: Quote block name, so it was easily visible.
py, unix: Add -v option, print bytecode dump if used.

This will work if MICROPY_DEBUG_PRINTERS is defined, which is only for
unix/windows ports. This makes it convenient to user uPy normally, but
easily get bytecode dump on the spot if needed, without constant recompiles
back and forth.

TODO: Add more useful debug output, adjust verbosity level on which
specifically bytecode dump happens.
py-version.sh: Make it work in case no git tag is present.
tests: Add framework for comparative benchmarking.

Motivation is optimizing handling of various constructs as well as
understanding which constructs are more efficient in MicroPython.
More info: http://forum.micropython.org/viewtopic.php?f=3&t=77

Results are wildly unexpected. For example, "optimization" of range
iteration into while loop makes it twice as slow. Generally, the more
bytecodes, the slower the code.
tests/bench/var: Add tests for class/instance var access.

Also compared with method abstraction for accessing instance vars -
it's more than 3 times slower than accessing var directly.
py: Turn down amount of RAM parser and compiler use.

There are 2 locations in parser, and 1 in compiler, where memory
allocation is not precise.  In the parser it's the rule stack and result
stack, in the compiler it's the array for the identifiers in the current
scope.  All other mallocs are exact (ie they don't allocate more than is
needed).

This patch adds tuning options (MP_ALLOC_*) to mpconfig.h for these 3
inexact allocations.

The inexact allocations in the parser should actually be close to
logarithmic: you need an exponentially larger script (absent pathological
cases) to use up more room on the rule and result stacks.  As such, the
default allocation policy for these is now to start with a modest sized
stack, but grow only in small increments.

For the identifier arrays in the compiler, these now start out quite
small (4 entries, since most functions don't have that many ids), and
grow incrementally by 6 (since if you have more ids than 4, you probably
have quite a few more, but it wouldn't be exponentially more).

Partially addresses issue #560.
Merge pull request #566 from turbinenreiter/master

added SDdatalogger example
examples, SDdatalogger: Add more comments; reduce power consumption.
Change references (in comments) of pyb.GPIO to be pyb.Pin

The documentation at http://micropython.org/doc/module/pyb/ExtInt should also be
updated.
Merge pull request #571 from dhylands/fix-extint-doc

Change references (in comments) of pyb.GPIO to be pyb.Pin
py-version.sh: Use --always option of git describe.
py: Comment exc_state member from mp_obj_gen_instance_t as it gives trouble

...to some compilers who can't process 2 zero-sized arrays in structs. It's
never referenced directly anyway.

See disussion on #568 as well.
modgc: Add new module for GC-related functionality.
stmhal: pyb: Use gc() function as defined by standard module "gc".

TODO: Get rid of this compatibility define and rely on standard module.
py: enumerate(): Add NotImplementedError for kwargs.

Addresses #577.
py: bytes(), str(): Add NotImplementedError for kwargs.

Addresses #567.
py: Add keyword arg support to enumerate constructor.

Need to have a policy as to how far we go adding keyword support to
built ins.  It's nice to have, and gets better CPython compatibility,
but hurts the micro nature of uPy.

Addresses issue #577.
Merge branch 'master' of https://github.com/micropython/micropython

Conflicts:
	py/argcheck.c
	py/objenumerate.c
	py/runtime.h