Adds functions to sys to be compatible with JSB
Merge pull request #791 from ricardoquesada/sys_additions

Adds functions to sys to be compatible with JSB
add support for audio format - mp4,m4a
Merge remote-tracking branch 'cocos2d-html5/master' into issue1569_audioJSB
fixed #1569 add support for audio format - mp4,m4a
Accelerometer
Merge pull request #792 from ShengxiangChen/issue1569_audioJSB

fixed #1569 add support for audio format - mp4,m4a
Merge pull request #793 from ShengxiangChen/issueXXX_AccelerateForHTML5AndJSB

Accelerometer bug
add .gitignore to use WebStorm comfortably
add a new Macro: cc.DEVICE_PIXEL_RATIO