Get tests working for Python 3

Also work for some other environments, but some still aren't
finding any tests.

Also, I had to relax the permission checking on the edit
pagelets view; it was checking for a per-object permission
but apparently that hasn't been implemented or not hooked up.
Merge branch 'python-3' of github.com:caktus/django-pagelets into python-3

Conflicts:
	pagelets/tests/urls.py