texture refactoring
Merge branch 'master' of https://github.com/bearkode/PrisonBreak

Conflicts:
	PBKit/PBKit/PBRenderable.h
	PBKit/PBKit/PBRenderable.m
Merge branch 'master' of https://github.com/bearkode/PrisonBreak

Conflicts:
	PBKitTest/PBKitTest/Classes/PVRTextureView.m