[clone] Allow cloning unparented actors
[clone] Allow cloning unparented actors

If the source of a ClutterClone does not have a parent actor the
clone will be unable to paint it because it's missing an allocation.

A simple way to fix it is to make the ClutterClone act like a
"foster parent": when it is allocated it will check if the source
actor has a parent and if not it will allocate the source with
its preferred size.

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