Cleanup some imports and prepare imports for python3
Python2.5 and Python3 compatible exception
Add StringIO to our shim
More work getting python 3 working
More manipulating string types to get a working python3 build
Add Python3 to tox file
Cleanup and docs for our shim
Don't automatically cast headers to str()
Add Python 3.3 to setup.py
Add PyPy to the setup.py list since we test it through tox
Set the Development Status to Beta
Add support for Python3.3

Fixes #20