OO-2069: delegate the create controller to the repository entry handler with a default implementation

OO-1593: feedback in test need cut value, fix case of test with several test parts, and degenerated test part

OO-2057 fix more nullpointers when no binder and sections is available, styling ep start page, entries listing, binder listing, adding de translations

OO-2057: adapt the course element for the new binder, the assessment tool to view the details of the new binder and the binder resource

enable floating entries with ownership

OO-2052: remove group memberships first to prevent timing issue with the asynchronous removing of subscription (patch S. Clemenz)