Add UI widget expansion
Merge pull request #166 from hanrea/master

Add UI widget expansion
Merge pull request #167 from pandamicro/master

H5 doc rearrangement, prepare for 3.0a release
H5: Rearrange release note folder for html5
Merge branch 'master' of https://github.com/cocos2d/cocos-docs
H5: Add release note for v3.0a