Moritz Schlarb

Merged issue from #19 and #76 . The model can surely be improved by using advanced SQLAlchemy techniques. - [ ] [hybrid attributes](http://docs.sqlalchemy.org/en/latest/orm/extensions/hybrid.html) - [ ] `attribute_mapped_collection` - [x] Cascades...

Additional validation hooks for sprox/tgext.crud to ensure basic validity constraints and prevent mistakes such as e.g. removing oneself from the list of teachers. Related to #129.

More flexible filtering and sorting in SubmissionsController

3

like Redmine does with its issues: http://www.redmine.org/projects/redmine/issues

Same for teachers, tutors, etc. pp.

Instead of Team Names, or additionally...

#215 (Assignment.allowed_languages is showing more than the selected values) is only hackish fixed.