Remove 2to3
Remove StringIO for python3
Remove raw unicode which is not allowed in Python3.
Explicit list call for Python 3.
Remove basestring reference for Python 3.
Update tests for Python 3.
Isolate all compatibility code.
Nevermind, Python 2.7 has io module.
Error message on installation to wrong Python version.
Merge branch 'python3'

Remove the use of 2to3 and make everything straight Python2-compatible
Python3.
Bump version.