Update django-filter integration

Merged upstream 0.9.8 changes for the templates we are shipping.
Cleaned up content navbar to match the other applications, still other
parts like actions and popup forms button are different than the main app.
Any actual django-filer user is more than welcome to clean this up more.

Fix #158
Reduce content_title block scope

To not include the hamburger menu but just the title. Needed for
django-filer updates.
Update CHANGELOG
test project: add django-filer

So it's easier to see if we break it