Fix: don't use depth testing when no depth buffer will be used.
Fix: don't use depth testing when no depth buffer will be used.

Former-commit-id: 936c24f73355a9e6cb7ed09ef1626bd6e915baf0
finthamoussu/cocos2d-objc,finthamoussu/cocos2d-objc,TukekeSoft/cocos2d-spritebuilder,seem-sky/cocos2d-swift,nader-eloshaiker/cocos2d-objc,tambarskjelve/cocos2d-objc,yaoxiaoyong/cocos2d-objc,lpeancovschi/cocos2d-objc,finthamoussu/cocos2d-objc,oxeron/cocos2d-objc,SuPair/cocos2d-objc,liduanw/cocos2d-objc,jason-puck/cocos2d-iphone,liduanw/cocos2d-objc,seem-sky/cocos2d-swift,richardgroves/cocos2d-iphone,savysoda/cocos2d-objc,knight2010/cocos2d-objc,SuPair/cocos2d-objc,finthamoussu/cocos2d-objc,seem-sky/cocos2d-swift,knight2010/cocos2d-objc,richardgroves/cocos2d-iphone,codepython/cocos2d-objc,lpeancovschi/cocos2d-objc,cogddo/cocos2d-objc,DNESS/cocos2d-objc,zaneLou/cocos2d-objc,savysoda/cocos2d-objc,yaoxiaoyong/cocos2d-objc,DNESS/cocos2d-objc,nader-eloshaiker/cocos2d-objc,TukekeSoft/cocos2d-spritebuilder,savysoda/cocos2d-objc,nader-eloshaiker/cocos2d-objc,liduanw/cocos2d-objc,richardgroves/cocos2d-iphone,dnessorga/cocos2d-objc,seem-sky/cocos2d-swift,zaneLou/cocos2d-objc,jason-puck/cocos2d-iphone,SuPair/cocos2d-objc,lpeancovschi/cocos2d-objc,knight2010/cocos2d-objc,TukekeSoft/cocos2d-spritebuilder,tambarskjelve/cocos2d-objc,jason-puck/cocos2d-iphone,yaoxiaoyong/cocos2d-objc,cogddo/cocos2d-objc,tambarskjelve/cocos2d-objc,tambarskjelve/cocos2d-objc,zaneLou/cocos2d-objc,zaneLou/cocos2d-objc,yaoxiaoyong/cocos2d-objc,codepython/cocos2d-objc,DNESS/cocos2d-objc,dnessorga/cocos2d-objc,liduanw/cocos2d-objc,codepython/cocos2d-objc,tambarskjelve/cocos2d-objc,cocos2d/cocos2d-objc,TukekeSoft/cocos2d-spritebuilder,DNESS/cocos2d-objc,knight2010/cocos2d-objc,lpeancovschi/cocos2d-objc,DNESS/cocos2d-objc,liduanw/cocos2d-objc,dnessorga/cocos2d-objc,SuPair/cocos2d-objc,SuPair/cocos2d-objc,oxeron/cocos2d-objc,savysoda/cocos2d-objc,dnessorga/cocos2d-objc,yaoxiaoyong/cocos2d-objc,nader-eloshaiker/cocos2d-objc,cocos2d/cocos2d-objc,cogddo/cocos2d-objc,dnessorga/cocos2d-objc,codepython/cocos2d-objc,cogddo/cocos2d-objc