It defines types used by all other headers. Fixes #691.
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/.
Enumerates CDC device over USB, but doesn't transmit/receive yet.