Merge pull request #686 from dingpinglv/Iss5781_V3rc2

Fixed #5781: update the reference of cocos2d-html5
[3.0 RC2 RLEASE] Add release note and upgrade guide
Merge pull request #689 from pandamicro/master

[3.0 RC2 RLEASE] Add release note and upgrade guide
Update html5 engine
Issue #5781: Add reflection to templates
Issue #5781: Fix typo
Merge pull request #690 from pandamicro/master

Issue #5781: Add reflection to templates
Issue #5781: Add search path for plugin-x bindings
Update html5 engine
Merge branch 'master' of https://github.com/cocos2d/cocos2d-js
Merge pull request #691 from pandamicro/master

Issue #5781: Add search path for plugin-x bindings
Closed #5781: update the reference of cocos2d-html5