Merge pull request #211 from dingpinglv/Iss_ReleaseNote

fixed a typo in cc.loader
Base concept of Cocos2d-x 3.0
fix the name of the directory
Transitions of scenes in Cocos2d-x 3.0
Merge branch 'master' of https://github.com/cocos2d/cocos-docs
Merge pull request #212 from u0u0/master

Two articles of Cocos2d-x 3.0
issue #4527, add a new article about how to build android project with eclipose
issue #4527, finish the android article
fixed #4527. finish
Merge pull request #215 from andyque/master

#issue 4527. add a new document
Update en.md
Fixed: update upgrade guide of Cocos2d-JS v3.0a for ccs.UILayer