requested to merge jadahl/mutter:wip/remove-clutter-state-alpha-animation into master
Deprecated since years back and unused. From their documentation:
ClutterState is an object controlling the tweening of properties on multiple actors between a set of named states.
ClutterAlpha is a class for calculating an floating point value dependent only on the position of a #ClutterTimeline.
ClutterAnimation is an object providing simple, implicit animations for GObjects.