Texture2D: Do not use RGBA888 when no alpha
Texture2D: Do not use RGBA888 when no alpha

Instead use RGB565 like in v1.1.
RGB888 textures, internally, are expanded into 32-bit textures


Former-commit-id: 20a643a2684221071a322dde581fd5c503c31723
zaneLou/cocos2d-objc,finthamoussu/cocos2d-objc,dnessorga/cocos2d-objc,yaoxiaoyong/cocos2d-objc,dnessorga/cocos2d-objc,savysoda/cocos2d-objc,DNESS/cocos2d-objc,cogddo/cocos2d-objc,zaneLou/cocos2d-objc,seem-sky/cocos2d-swift,nader-eloshaiker/cocos2d-objc,SuPair/cocos2d-objc,dnessorga/cocos2d-objc,cocos2d/cocos2d-objc,finthamoussu/cocos2d-objc,liduanw/cocos2d-objc,cogddo/cocos2d-objc,yaoxiaoyong/cocos2d-objc,lpeancovschi/cocos2d-objc,dnessorga/cocos2d-objc,zaneLou/cocos2d-objc,tambarskjelve/cocos2d-objc,DNESS/cocos2d-objc,zaneLou/cocos2d-objc,seem-sky/cocos2d-swift,savysoda/cocos2d-objc,jason-puck/cocos2d-iphone,jason-puck/cocos2d-iphone,TukekeSoft/cocos2d-spritebuilder,richardgroves/cocos2d-iphone,tambarskjelve/cocos2d-objc,cogddo/cocos2d-objc,TukekeSoft/cocos2d-spritebuilder,SuPair/cocos2d-objc,oxeron/cocos2d-objc,nader-eloshaiker/cocos2d-objc,DNESS/cocos2d-objc,knight2010/cocos2d-objc,lpeancovschi/cocos2d-objc,codepython/cocos2d-objc,finthamoussu/cocos2d-objc,yaoxiaoyong/cocos2d-objc,seem-sky/cocos2d-swift,liduanw/cocos2d-objc,yaoxiaoyong/cocos2d-objc,codepython/cocos2d-objc,knight2010/cocos2d-objc,richardgroves/cocos2d-iphone,cocos2d/cocos2d-objc,DNESS/cocos2d-objc,tambarskjelve/cocos2d-objc,dnessorga/cocos2d-objc,nader-eloshaiker/cocos2d-objc,knight2010/cocos2d-objc,nader-eloshaiker/cocos2d-objc,seem-sky/cocos2d-swift,oxeron/cocos2d-objc,yaoxiaoyong/cocos2d-objc,cogddo/cocos2d-objc,lpeancovschi/cocos2d-objc,jason-puck/cocos2d-iphone,tambarskjelve/cocos2d-objc,liduanw/cocos2d-objc,liduanw/cocos2d-objc,SuPair/cocos2d-objc,savysoda/cocos2d-objc,TukekeSoft/cocos2d-spritebuilder,codepython/cocos2d-objc,SuPair/cocos2d-objc,knight2010/cocos2d-objc,lpeancovschi/cocos2d-objc,liduanw/cocos2d-objc,tambarskjelve/cocos2d-objc,DNESS/cocos2d-objc,finthamoussu/cocos2d-objc,codepython/cocos2d-objc,SuPair/cocos2d-objc,TukekeSoft/cocos2d-spritebuilder,savysoda/cocos2d-objc,richardgroves/cocos2d-iphone