Use BeautifulSoup 4

BeautifulSoup import is the third version, which was a dependency of
django-fusionbox.
Use widgy queryset on ReviewedVersionCommit
Add django argonauts dependency
Remove fusionbox.middleware.GenericTemplateFinderMiddleware dependency

This middleware have meen moved to
git://github.com:fusionbox/django-fusionbox.git@f6147ab
Get rid of django-fusionbox in the documentation