Now of the form MICROPY_PY_*.  See issue #35.

.makefile() should allow to specify which stream time to create - byte
or text.

Caveat is that __new__ should recurse to base class __new__, and ultimately,
object.__new__ is what handles instance allocation.

MP_ALLOC_* -> MICROPY_ALLOC_*
MICROPY_PATH_MAX -> MICROPY_ALLOC_PATH_MAX
MICROPY_ENABLE_REPL_HELPERS -> MICROPY_HELPER_REPL
MICROPY_ENABLE_LEXER_UNIX -> MICROPY_HELPER_LEXER_UNIX
MICROPY_EXTRA_* -> MICROPY_PORT_*

See issue #35.

Also, define object.__init__() (semantically empty, purely CPython compat
measure). Addresses #520.

See issue #608 for justification.

io.FileIO is binary I/O, ans actually optional. Default file type is
io.TextIOWrapper, which provides str results. CPython3 explicitly describes
io.TextIOWrapper as buffered I/O, but we don't have buffering support yet
anyway.

Now schedule is: for native types, we call ->make_new() C-level method, which
should perform actions of __new__ and __init__ (note that this is not
compliant, but is efficient), but for user types, __new__ and __init__ are
called as expected.

Also, make sure we convert scalar attribute value to a bound-pair tight in
mp_obj_class_lookup() method, which avoids converting it again and again in
its callers.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>

This time, in mp_seq_cmp_bytes(). How many more cases are still lurking?

Done in generalized manner, allowing any stream class to be specified as
working with bytes.

sep=None is TODO.

This should now have correct (and optimal) behaviour.

Addresses issue #610.

Debugging output for emit_glue now simplified so that the init and
deinit functions are no longer needed.

__debug__ now resolves to True or False.  Its value needs to be set by
mp_set_debug().

TODO: call mp_set_debug in unix/ port.

TODO: optimise away "if False:" statements in compiler.

Infra for counts of other types is there, need last mile to be implemented.

Fix some unused variables, and silence a clang warning about initialization override in vmentrytable.h

It's a hack, but can't find a cleaner way to do it.

Having both MP_OBJ_NOT_SUPPORTED and MP_OBJ_NULL is arguably confusing.

This is better than forcing each getiter() implementation to raise exception.

Updated functions now do proper checking that n_kw==0, and are simpler
because they don't have to explicitly raise an exception.  Down side is
that the error messages no longer include the function name, but that's
acceptable.

Saves order 300 text bytes on x64 and ARM.