fixing ccNode.setScale when scaleY === 0
fixing ccNode.setScale when scaleY === 0
Merge branch 'setScaleFix' of github.com:MarkEHenderson/cocos2d-html5 into setScaleFix

Conflicts:
	cocos2d/base_nodes/CCNode.js
Merge pull request #1007 from MarkEHenderson/setScaleFix

Fixes ccNode.setScale when scaleY === 0