LDEV-1251, LDEV-1064. Refactored the way lessons are retrieved for the index page (fixed LDEV-1064); added interface 1.2 (jquery extension), allowing sorting of lessons via drag and drop (LDEV-1251); added ordered_lesson_ids column to lams_organisation (LDEV-1251).
LDEV-1348: Tweaking the db handling of branch activity mappings. If a user deletes and then readds an identical mapping for grouped based branching, we get a new entry created and the old entry deleted. Can't guarantee what order Hibernate will persist the changes to the db, so e can't have a unique key on group/sequence on the table.