alsa-gobject: misc fixes and documentation for system calls

alsa-project/alsa-gobject pull request #34 was opened from takaswie:

This patchset includes misc fixes and documentation for system calls for each methods.

Request URL : https://github.com/alsa-project/alsa-gobject/pull/34 Patch URL : https://github.com/alsa-project/alsa-gobject/pull/34.patch Repository URL: https://github.com/alsa-project/alsa-gobject