[Muine] M4A mime detection

[Matthew Good <muine matt-good net>]

I built Muine with m4a support enabled, but I've been unable to play the
songs in it.  It looks like Gnome isn't detecting the mime type of the
m4a files (in Nautilus the properties dialog shows
application/octet-stream) so Muine ignores the files.

I'm using Ubuntu/Gnome 2.8, and I can see the m4a entries in
gnome-vfs.mime and gnome-vfs-mime-magic, so I'm not sure what I'm
missing here.

-- 
Matthew Good <muine matt-good net>