http://code4app.com/article/cocoapods-install-usage
http://www.360doc.com/content/14/0309/10/11029609_358970353.shtml
AFNetWorking:
https://github.com/AFNetworking/AFNetworking
CocoaPods
原文：http://www.cnblogs.com/developer-qin/p/4362497.html
