iOS HTTP Connection Async

http://stackoverflow.com/questions/8427836/how-to-make-program-wait-for-asynchronous-nsurlconnection-to-finish-before-proce
https://github.com/bwship/async-http-client-ios
http://blog.slaunchaman.com/2011/07/19/asynchronous-synchronous-requests-effortless-networking-code/
http://chrisrisner.com/assigning-a-block-for-each-url-connection-in-ios