issue #3690: Rewrite CCNS.js
Merge pull request #1485 from SmallAiTT/iss3690_ccns_dev3.0

issue #3690: Rewrite CCNS.js
Fixed #3838: Allow retina display only on apple device to resolve the bug
Merge branch 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5 into develop

Conflicts:
	cocos2d/cocoa/CCNS.js
Merge pull request #1513 from pandamicro/develop

Merge develop to develop-3.0
Merge branch 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5 into 3836_scheduler_dev
issue #3836 Refactor CCScheduler. Delete some common functions.  Rename some common functions and move them to CCCommon.js.