New podspec for FSNetworking

FSN is a small library for HTTP networking on iOS. It comprises a single class, FSNConnection, and several small Cocoa Foundation categories. FSNConnection uses NSConnection, blocks, and NSConnection's operation queue delegate or GCD.

Note: Although the README claims that FSNetworking is at version 1.0, the maintainer hasn't tagged it as such.  I have submitted an issue asking him to do so.