Working date filter, last test filter
Reorganze filter structure, every filter is responseible for filtering. Escape readds buttons
Merge branch 'master' of github.com:SimonEbner/ba

Conflicts:
	frontend/src/app.coffee
	frontend/src/collections/testGroups.coffee
	frontend/src/collections/tests.coffee
	frontend/src/models/numberFilter.coffee
	frontend/src/models/test.coffee
	frontend/src/models/testGroup.coffee
	frontend/src/views/dateFilterView.coffee