fixed #2531 Asynchronous loading resources for rendering classes has been implemented.
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss2531_AutoLoadResourcesForCCBReader

Conflicts:
	cocos2d/sprite_nodes/CCSprite.js
	cocos2d/sprite_nodes/CCSpriteFrame.js
fixed #2531 Asynchronous loading texture for LabelBMFont on Canvas Mode has been implemented
fixed #2531 use direct calling function of parent class instead this._super
fixed #2531 Async loading textures for cc.LabelBMFont has been implemented.
Merge pull request #1090 from dingpinglv/Iss2531_AsyncLoadingTextures

fixed #2531 Asynchronous loading textures for rendering classes has been implemented