vertex: Register progress function
vertex: Register progress function

This allows animating properties storing a ClutterVertex.

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