ctl: enhancement for error reporting

alsa-project/alsa-gobject pull request #48 was opened from takaswie:

Current implementation uses library-wide error domain to report error, however this is partly against rule of GError usage. Furthermore, the error delivers information just about errno and hard to know the cause of error.

This patchset enhances error reporting. The library-wide error domain is obsoleted. A new error domain is added just for ALSACtl.Card. The error domain delivers information about the cause of error.

Request URL : https://github.com/alsa-project/alsa-gobject/pull/48 Patch URL : https://github.com/alsa-project/alsa-gobject/pull/48.patch Repository URL: https://github.com/alsa-project/alsa-gobject