Feature #5253: Add constructor support and constants for AssetsManager's events
Feature #5253: Add retain release for AssetsManager and Manifest
Feature #5253: Fix auto binding issues
Feature #5253: Add manifest files
Feature #5253: Add js test case for AssetsManager
Update submodules
Merge branch 'master' of https://github.com/cocos2d/cocos2d-js
Merge pull request #409 from pandamicro/master

Feature #5253: Add jsbinding support and js test case for AssetsManager