devilry_gradingsystemplugin_approved: Use bulkviewbase.
Merge branch 'new-examiner' of github.com:devilry/devilry-django into new-examiner
devilry_gradingsystemplugin_approved: Error handling in bulk view.
devilry_gradingsystemplugin_approved: More work on bulk editing.
devilry_examiner|gradingsystem: Gracefully handle selected_group_ids in session.