Merging GnomeVolumeControl in libgnome-desktop

[Giovanni Campagna <scampa giovanni gmail com>]

Hello Shell and Control Center developers

I've stumbled upon https://bugzilla.gnome.org/show_bug.cgi?id=675902,
which is a bug about the volume menu in gnome-shell, and I had to
update some of the copy-pasted bits from libgnome-volume-control.
What I found out is that the trees in gnome-shell and
gnome-control-center had diverged, with one missing features and the
other having bugs with introspection. This situation is bad, in my
opinion, as it leads to work and code duplication.
Therefore I propose to merge libgnome-volume-control (at least the
shared GvcMixerControl and related parts) into libgnome-desktop, so
that it can be accessed by all interested core modules. Alternatively,
we could setup a libgnome-volume-control git module, and use git
submodules to access it, like we do for libgd and libgsystem.

What do you think?
If there are no objections, I'll prepare a patch for libgnome-desktop.
I will probably rename Gvc to Gnome, as required by introspection, and
thus prepare an update for the affected modules.

Cheers

Giovanni