initial version of serialization/unserialization
Merge branch 'next' of github.com:cocos2d/cocos2d-html5 into next

Conflicts:
	cocos2d/core/base-nodes/BaseNodesPropertyDefine.js
	cocos2d/core/labelttf/LabelTTFPropertyDefine.js
serializer for nodes
Merge branch 'next' of github.com:cocos2d/cocos2d-html5 into next
Merge pull request #2497 from pandamicro/next

Fix LabelTTF dependency issue
Merge pull request #2498 from Wu-Hao/next

serializer for nodes
Improve the engine to support GameEngine