OO-1424: remove subscriptions if a member is removed from a group or a course, or a group is removed from the relations to a course

OO-1349: filter the tree to select the start course element, use the runstructure instead of the editortreemodel, remove the lockMode ( as security ), ips and keys mandatory if options checked

OO-1408: add last modified date in efficiency statements list, add link to courses in user management, add coaching button in user management

OO-1417: inline the details of the QTI results file in the assessment tool to make it print friendly

OO-1426 move styles that can be used in html editor to a separate scss file which is included in content and in the theme to render in iframe and in main window

OO-1408: improve performance with native SQL queries, add all queries needed for authors to see their courses and the groups linked to their courses

OO-1416: check the soft key with the test soft key without querying the database, survive corrupted course if one is found in the list of references of the tests