Fixed unicode literals in migrations
Removed references to python2 only string types
Use relative imports (PEP328)
Use six to import urllib and StringIO
Fixed unicode literals in edit handlers
Use six.with_metaclass to add metaclass to Page
Python 3 doesn't suport dict.iteritems()
Fixed Python3 incompatible dictionary concatentation
Changed __unicode__ methods to __str__
Modified setup.py for python 3 support