updated some twitter classes to the 1.1 api

this implementation uses abraham williams' twitteroauth library: https://github.com/abraham/twitteroauth

the classes will probably change some more. i'm not 100% in love with how the twitter connection object is created and passed into each class that uses the API, but i'm not sure of a better alternative yet. maybe it will come to me when I work on API calls that write to twitter.