Change all UILabels now use system font
Change downloading of episodes now uses AFNetworking

To start downloading episodes use downloadEpisodeWithURL:saveToURL:downloadProgress:success:failure: method located in IGHTTPClient. The download method also make use of AFNetwork's built in network reachability for checking network status. This also address issue #11 a local notification is now fires if the app is in background state and a download succeeds or fails.
Change downloading with cellular data is defaulted to NO
Fix streaming table view cell's selection style is now set using the correct value
Change the published text now aligns up with episode title