https://github.com/facebook/pop
http://www.cocoachina.com/industry/20140507/8339.html
http://www.ui.cn/project.php?id=21148
http://blog.csdn.net/u013741809/article/details/38511741
http://geeklu.com/2014/05/facebook-pop-usage/
原文：http://www.cnblogs.com/willbin/p/4231758.html