fixed #2082 fixed a bug of cc.SpriteBatchNode about zOrder, fixed a bug of cc.Sprite's setFlipX/Y on Canvas Mode
Merge pull request #918 from dingpinglv/Iss2082_FixSomeBugs

fixed #2082 fixed a bug of cc.SpriteBatchNode about zOrder, fixed a bug of cc.Sprite's setFlipX/Y on Canvas Mode