Dependency bump for Clutter for Gnome 2.28

["Jason D. Clinton" <me jasonclinton com>]

Okay to bump official depends on Clutter and Clutter-GTK from the
0.8.x API to 0.9/1.0 API? I fully expect it to stabilize and have a
1.0 release before 2.28. Also, Clutter Cairo is now part of Clutter.

Also, it's unclear from reading the archives but is libcanberra
blessed now? Planning on using it as a poor man's replacement for SDL
mixer...