Added OATH, cleaned up curl for GET/POST, and more

[mmrk09]

Hello,

Great library it was just missing a few things for my requirements. I've added OATH support and cleaned up the curl interface, it now also supports get/post/delete/put calls so it can be easily expanded for adding more stub GET/POST/DELETE methods too. Adjusted getNext() so it's easy to iterate over more responses and stored the response internally.

Updated the Readme as well to include new information and quick start guide using OATH. I also want to add more functionality down the road but this is where I'm at now. Welcome more testing and improvements.

Would like to add member variables and beef up the object as well but don't have time right now.