WIP: Cache absolute transformation matrices of ClutterActor
This MR starts caching the absolute transformation matrices (more specific: The complete modelview + projection matrix), it cuts down CPU time spent building those matrices by about 50% in cases where lots of actors are moving.
Depends on !1276 (merged) (included), !1267 (merged), gnome-shell!1308 (merged)
WIP since this depends on another fix
Edited by Jonas Dreßler