BUG(1974): Fix error handling in FLAC read callback.
OTHER: Resurrect the ringbuf xform.
OTHER: Make ringbuf xform buffer size configurable.
BUG(1789): Handle XRUN/SUSPEND in xmms_alsa_format_set.
OTHER: Use snd_pcm_recover in instead of homegrown.
OTHER: Initial relative_volume var in cli.
OTHER: Add a XMMS_CALL macro for simple invocation in the cli.
OTHER: Use while loops for iterators in the cli.
OTHER: Move list_plugins to commands.c in the cli.

Also applies sorting and columned print, hardcoded width for now.
OTHER: Add XMMS_CALL_CHAIN macro.

Also moves the newly introduced XMMS_CALL into the new header.
OTHER: Use XMMS_CALL_CHAIN where applicable.
OTHER: Clean up the CLI commands/helpers.

Crappy commit, but the CLI was a huge intertwined mess. Now all
sub-commands are in their own file, and utils.c has been cut down
to just a fraction of its size. A ton of util/command APIs have been
cleaned up do less more clearly or nuked, and try to avoid using big
fat structs as parameters and instead be more specific.
OTHER: Add beginning of an integration test for the cli.
OTHER: Don't convert xmmsv_t to GArray for playlist cache in cli.
OTHER: Move command_context_t related code to command_utils.c.

Should probably rename command_utils.c as well, but that's for later.
OTHER: Intersect query with playlist where applicable.
OTHER: Remove typedef of GOptionEntry in cli.
OTHER: Move command_context_t typedef to command_utils.h.
OTHER: Remove unused include in matching_browse.c.