actor: Ensure the validity of the queue_redraw_entry pointer
actor: Ensure the validity of the queue_redraw_entry pointer

In _clutter_actor_queue_redraw_with_clip, there was the possibility that
the actor will add itself to the stage's redraw queue without keeping track
of the allocated list member.

In clutter_actor_unparent, the redraw queue entry was being invalidated
before the mapped notify signal was being fired, meaning that queueing a
redraw of an unmapped actor in the mapped notification callback could
cause a crash.

http://bugzilla.clutter-project.org/show_bug.cgi?id=2621

djdeath/clutter-multithreaded,djdeath/clutter-android,spatulasnout/clutter,GNOME/clutter,spatulasnout/clutter,jigpu/clutter,djdeath/clutter-multithreaded,heysion/clutter-clone,spatulasnout/clutter,spatulasnout/clutter,Distrotech/clutter,collects/clutter,heysion/clutter-clone,heysion/clutter-clone,Distrotech/clutter,djdeath/clutter,collects/clutter,heysion/clutter-clone,djdeath/clutter-android,GNOME/clutter,Distrotech/clutter,ebassi/clutter,kerrickstaley/clutter-vala,jigpu/clutter,ebassi/clutter,ebassi/clutter,dlespiau/clutter,GNOME/clutter,spatulasnout/clutter,collects/clutter,Distrotech/clutter,ebassi/clutter,GNOME/clutter,djdeath/clutter-multithreaded,collects/clutter,kerrickstaley/clutter-vala,djdeath/clutter-android,dlespiau/clutter,dlespiau/clutter,djdeath/clutter-multithreaded,djdeath/clutter-android,djdeath/clutter-android,kerrickstaley/clutter-vala,jigpu/clutter,collects/clutter,djdeath/clutter,GNOME/clutter,jigpu/clutter,djdeath/clutter,heysion/clutter-clone,kerrickstaley/clutter-vala,jigpu/clutter,djdeath/clutter,Distrotech/clutter,jigpu/clutter,Distrotech/clutter,djdeath/clutter,djdeath/clutter,ebassi/clutter