[Cocos2d-JS]Update upgrade guide
[Cocos2d-JS]Update upgrade guide again
[Cocos2d-JS]Update upgrade guide again and again
[Cocos2d-JS]Update upgrade guide title
Merge branch 'master' of https://github.com/cocos2d/cocos-docs
Merge pull request #239 from pandamicro/master

[Cocos2d-JS]Update upgrade guide