This patch implements support for class methods __delattr__ and __setattr__
for customising attribute access. It is controlled by the config option
MICROPY_PY_DELATTR_SETATTR and is disabled by default.
Several ports use identical code for the 1-argument form of the builtin
help function. Move this code to a library function to allow easier
re-use by ports.
Move definition of mp_builtin_open_obj to a separate module, then file.c
becomes more or less compartmentalized FatFs file class, which can be used
together with file class implementations for other (V)FSes.
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/.