Merge pull request #1760 from dingpinglv/Iss4757_ReleaseAlpha2

Issue #4757: fixed a bug of cc.TextFieldTTF that it can't present on Canvas.
Issue #4608: Fixed a bug that cc.log can‘t print on the page.
Issue #4608: Remove the debugging code
Merge pull request #1761 from VisualSJ/develop-3.0

Issue #4608: Fixed a bug that cc.log can‘t print on the page
Issue #4608: Fixed a bug that mobile ff coordinate error
Merge pull request #1762 from VisualSJ/develop-3.0

Issue #4608: Fixed a bug that mobile ff coordinate error
Fixed #4706: Fixed a problem due to IE incompatible issue
Merge branch 'develop-3.0' of git://github.com/cocos2d/cocos2d-html5 into develop-3.0
Merge pull request #1763 from pandamicro/develop-3.0

Fixed #4706: Fixed a problem due to IE incompatible issue
Issue #4757: add an assert to cc.Sprite for debug friendly.