Breaking all twitter classes out into their own package.

This is done without breaking exsiting functionality or imports by doing imports
in the twitter/__init__.py file.

user.py imports Status and status.py import User
In order to prevent cyclic import errors, they are imported only if they are
actually used.

Also, sys was not imported in the setup.py file, causing setup.py to fail if
setuptools can't be imported.
removing commented out imports
fixing merge conflicts and even a couple oddities that were probably bugs
merge issues from v1.3.1 build