Merge pull request #912 from dingpinglv/Iss2082_FixSomeBugs

fixed #2082 fix a bug of cc.Node when set negative scale to cc.Node
fixed #2082 correct a mistake for cc.LabelBMFont's static function
Merge branch 'master' of https://github.com/cocos2d/cocos2d-html5 into Iss2082_FixSomeBugs