The association is inactive, as in it doesn't do anything yet, but it
will later be used to determine what frame clock should be driving the
timeline by looking at what stage view the actor is currently on.
This also adapts sub types (ClutterPropertyTransition) to have
constuctors that takes an actor just as the new ClutterTimeline
constructor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
In cogl use cogl-config.h and in clutter use clutter-build-config.h. We
can't use clutter-config.h in clutter because its already used and
installed.
https://bugzilla.gnome.org/show_bug.cgi?id=768976
