re-pcre: sub(): If suffix of string matched, None was returned.
make_metadata.py: Allow to have module name != distribution name.

Like, micropython-re-pcre hosts re.py.
http.client: Add pristine from CPython 3.3.3.
http.client: Explicitly check for str type instead of "encode" method.

MicroPython string type shares setup with bytes, and thus both have entries
for "encode" and "decode" (but only one valid for a type really works).
http.client: Comment out io.RawIOBase, as uPy lacks complete io hierarchy.
http.client: Add basic example.