用Runtime写的分类:
https://github.com/ISMeSAM/-tabBarItem-badgeValue-
https://github.com/ISMeSAM/SAMUIAlertViewEx
https://github.com/ISMeSAM/RemoveButtonHighlightedEffect
https://github.com/ISMeSAM/SAMActionSheet
原文：http://www.cnblogs.com/wolfman4secret/p/4767591.html