New menu item: My classes and courses

This should show a list with all groups the currently logged in person is an owner of and link them to the week view of the according objects.

changed milestone to %1.0a1

added part::frontend source::customer type::feature labels

assigned to @hansegucker

created merge request !89 (merged) to address this issue

mentioned in merge request !89 (merged)

closed via merge request !89 (merged)

mentioned in commit 5922181b