Py3: Add tests for dt.distance_of_time_in_words examples.
Py3: Add tests for rest of examples.
Py3: Upgrade six to v1.4
Py3: Update Django versions to most recent ones for tox.
Py3: Add Django 1.6 to list of supported versions.
Py3: Test by Travis for Python 2.7 and 3.3
Py3: Cleanup doc (remove old links, remove reference to TurboGears).