Requests Merge


So what started as an attempt to post pictures to twitter has now started as this: A complete replacement of the API class method _FetchUrl with the method _RequestUrl. 

Here are some of the highlights:
 - Replaced a ~100 line function with a ~10 line function.
 - An almost complete removal of using urllib2
 - The ability to use multipart formdata easily (post_with_media)

Here are some issues:
 - Debugging Urls is broken at the moment
 - Caching was not added

Also, this merge adds in the beginnings of removing the OAuth2 library. More about that can be found in [this](https://github.com/jarobins/python-twitter/tree/working/) branch.