Closes #74

Use tabbed-view for ak list, too
Reduce code duplication between submission overview and ak list
Cleanup filtering in view
Display message when (filtered) AK list is empty
Remove submission button from dashboard when event is inactive
Closes #70

Hide wall (hide button in plan, redirect when calling directly)
Show message on normal plan & hide current and next AKs
Link only a single schedule view in Dashboard but not current AKs and wall
Update translations

adjust other buttons
re-generate translations

Adapt dashboard links to new URL structure of plan
Introduce conditional loading of paths to central URL file

fix typo

Introduce model
Introduce admin interface
Show buttons on dashboard start page

Add little space between the buttons

deploy dashboard under /
create template view
provide template with important links for each event
handle case of no events
create template tag to ensure installed apps