Added budgetitem model
Removed BudgetAssignment
Added views for budget items and added them to the project view
Handling 'opdrachtsom' in the right way
Hiding hidden projects in project overview for non-managers
Showing link to private projects again.
TODO: fix this on the booking page
Fixed per-week caching.
Added duration logging
Compensating for sqlite
Better caching of person changes
Better caching of person changes
Added more logging for timing info
Switched to database cache backend.

I'd prefer memcached, but the python bindings don't build on python3
Added python3-memcached for memcache support.
Showing % invoiced versus contract amount on projects page
Not linking hidden projects on booking page
Updated changelog
Merge pull request #12 from nens/reinout-fons-feedback2

Reinout fons feedback2