We'll need a way to trigger a bell from within clutter for keyboard
accessibility features, add the necessary hooks to be able to call a
backend bell-notify method.
https://bugzilla.gnome.org/show_bug.cgi?id=788564
Mutter (and libmutter users) are the only users of this version of
cogl, and will more or less only use the cogl-1.0, cogl-2.0 and cogl
experimental API variants, and having the possibility of having
different API versions of the same API depending on what file includes
it is error prone and confusing. Lets just remove the possibility of
having different versions of the same API.
https://bugzilla.gnome.org/show_bug.cgi?id=768977
