Closed #4887: Modify cc.inputManager's mouseMove event that its button needn't pressed
Merge branch 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5 into Iss4887_MouseMove
Merge pull request #1787 from dingpinglv/Iss4887_MouseMove

Closed #4887: Modify cc.inputManager's mouseMove event that its button needn't pressed