issue #4221 remove cocostudio gui directory to ccui
issue #4221 rename gui namespace ccs to ccui
Merge branch 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5 into develop-3.0-new
Merge pull request #1632 from xingsenma/develop-3.0

issue #4221 rename gui namespace ccs to ccui