Added Python3 support. Now Python 2 or 3 can be used with the same code

The code is runnable with Python3 and Python2 now. Tested with Python 2.7 and Python 3.3.
Please write code in the future for Python 2 and 3, so both are supported
seems like it is already fixed in the repo:

https://github.com/mitsuhiko/werkzeug/blob/master/werkzeug/datastructures.py#L2611

if it is not fixed in a release, having a workaround would be good. maybe just monkeypatch it into werkzeug, if __bool__ is not there.