[material] avoid flushing the journal when just changing the color
[material] avoid flushing the journal when just changing the color

Whenever we modify a material we call _cogl_material_pre_change_notify which
checks to see if the material is referenced by the journal and if so flushes
if before we modify the material.

Since the journal logs material colors directly into a vertex array (to
avoid us repeatedly calling glColor) then we know we never need to flush
the journal when material colors change.

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