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.
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/.
alloca() is declared in alloca.h which als happens to be included by stdlib.h.
On mingw however it resides in malloc.h only.
So if we include alloca.h directly, and add an alloca.h for mingw in it's port
directory we can get rid of the mingw-specific define to include malloc.h
and the other ports are happy as well.
These are to assist in writing native C functions that take positional
and keyword arguments. mp_arg_check_num is for just checking the
number of arguments is correct. mp_arg_parse_all is for parsing
positional and keyword arguments with default values.
When querying an object that supports the buffer protocol, that object
must now return a typecode (as per binary.[ch]). This does not have to
be honoured by the caller, but can be useful for determining element
size.