alsa-python: API coverage documentation tool

alsa-python: API coverage documentation tool

The following patch is a python tool that shows how much of the
asoundlib API is being covered by the alsa-python binding. It works by
parsing the C source code and comparing with the official Doxygen
documentation from alsa website.

It will help the following users:
- alsa-python developers: know how is mapped the original C API, so
which python function/variable may be used.
- python binding developers: know how much of the C API is covered. It
could help for mistakes (free() instead of using
snd_ctl_card_info_free), know what is missing, and statistic interest ;)

From: Aldrin Martoq <amartoq@dcc.uchile.cl>