Changed api for main menu entries.
Enhanced http error pages using a classed based views.
Moved dashboard and select widgets view from projector to core app.
Also some small clean ups.
It is now possible to define a default state and to submit extra stylefiles and javascript files when defining a widget in an app. This is done by a new metaclass in openslides.utils.dispatch. Also fixed some other tests.
- Better config icon.
- Renamed media to files (only for GUI).
- Add datatable function for motion and asssignemnt overview table. Removed old filter/sorting code.
- Some more template styling work.
