Windows MSVC port

Extend the windows port so it compiles with the toolchain from Visual Studio 2013
py, compiler: Add basic support for A=const(123).

You can now do:

    X = const(123)
    Y = const(456 + X)

and the compiler will replace X and Y with their values.

See discussion in issue #266 and issue #573.
Draft approach towards resolving https://github.com/micropython/micropython/issues/560#issuecomment-42213955
Merge pull request #568 from stinos/windows-msvc-port

Windows MS Visual C port
stmhal: Add time.time() and time.localtime().

time.time: returns seconds since 1/1/2000, as an integer.

time.localtime: Returns 8-tuple: (year, month, date, hour, minute,
    second, weekday, yearday).
Add gc.enable, gc.disable; remove pyb.gc.
README: Add short overview of Python features supported.

Also, "upgrade" project to "early beta", and elaborate pyboard description.
README: Add articles, and update doc for deploying firmware.
Merge branch 'pfalcon-README-features-overview'
windows: Add modtime implementation
Merge pull request #575 from stinos/windows-modtime

Add modtime implementation for mingw
runtime0.h: Group binary ops by fives.

So one has some chance to convert numeric op code into symbol.
bytes: Implement comparison and other binary operations.

Should support everything supported by strings.
py: Fix base "detection" for int('0<hexdigit>', 16).
mingw: Fix compilation issues

- use lowercase windows.h
- fix for mingw32 using preprocessor-unfriendly definition of CLOCKS_PER_SEC
py: Rename byte_code to bytecode everywhere.

bytecode is the more widely used.  See issue #590.
stm: Reorder mpconfig.h header inclusion to get stm building.
stmhal: Fix setting of RTC: was BCD now BIN encoded.

Addresses issue #592.
py: Combine native emitters to 1 glue function; distinguish viper.

This patch simplifies the glue between native emitter and runtime,
and handles viper code like inline assember: return values are
converted to Python objects.

Fixes issue #531.
bare-arm: Change output file from flash.elf to firmware.elf.