Fixed #2833: refactor cc.Sprite's _rect to make its fault tolerance stronger
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss2833_ReturnNewObjectForFunciton
Merge pull request #1161 from dingpinglv/Iss2833_ReturnNewObjectForFunciton

Fixed #2833: refactor cc.Sprite's _rect to make its fault tolerance stronger