modify back button position to relative,or iPad mini can see this button
add stop background music or it won't stop.
change to relative position
Merge branch 'master' of https://github.com/cocos2d/cocos2d-js into fb_3rd
fixed removeChild bug for  performanceAnimationTest.js
change to relative position. or iPad can't see this label.
modify the label  position
add objctive-c at title
change getID() to getId() or iOS an OSX can't use.
Merge pull request #669 from wuzhiming/fb_3rd

fix some bugs