Python 3.x Compatibility

While I would love to have this Python 3.5 compatible, probably more feasible to make 2.7 and 3.3 compatible. From what I understand 3.3 is one of the easier py3 versions to maintain forward and backward projects.

We should use `six` sparingly and when needed to do conditional version blocks, treat py2 as the special case:

``` python
if six.PY2:
# Special code
else:
# Modern code
```

This way it allows py4 when released to fall back to py3 code which will probably be compatible.