[Desktop 12.10 Topic] Deprecate language-selector

[Sebastien Bacher]

Hey,

That's a leftover from precise but it would be good to use the upstream 
"region" panel code and deprecate language-selector next cycle (better 
to have capplets integrated in system settings that those "launchers" 
for standalone apps there).

We will maybe need some design input on the ui and to finish the coding 
part started this cycle.

Cheers,
Sebastien Bacher