Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
Only calcsize() and unpack() functions provided so far, for little-endian
byte order. Format strings don't support repition spec (like "2b3i").
Unfortunately, dealing with all the various binary type sizes and alignments
will lead to quite a bloated "binary" helper functions - if optimizing for
speed. Need to think if using dynamic parametrized algos makes more sense.
