Python has had a built-in json library since version 2.6, released in 2008. Tweepy's tests no longer include Python 2.5, so they're no reason to use simplejson.
This also removes a complicated import path that made every instance of Tweepy attempt to import a module that's not in requirements.
This commit also removes the json library as an attribute of the Parser object. Don't know what it was doing there, besides being unpythonic.
use standard json library
Tweepy no longer supports python 2.5