serialize upload of asyncronously loaded textures
serialize upload of asyncronously loaded textures

Rate limit the uploading of textures to stop if it uses more than 5ms
during one master clock iteration.

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