LDEV-1261: Fixing a lazy loading exception that started when we removed the hibernate session filter on the user role import. The organisation can't be passed in from the web layer as it isn't connected to the session, and so when it tries to get the user organisation from the organisation, it throws a lazy loading exception.
a few neat UI improvements for branching - utilise scroll pane in branching view + move the bin into the view with open + fixed up transition/system tool x/y positioning on-drop
Branching: Tweaking the branch objects so that the contribution flags are right for teacher chosen activities (and hence the button will appear to do the selection in monitoring) and some changes to make the teacher chosen screen logic easier.
Further work on the teacher chosen branching screen. This included ensuring that the tool sessions aren't created for the activities within a branch when a lesson is created (as the users aren't known in advance) and also ensuring that there is always a grouping object attached to a branching activity during a lesson so that the grouping logic doesn't have to create it.
Branching: Create the Teacher Chosen branching screen, based on the existing Chosen Grouping screen. Not working yet but the changes have required changing the LessonService (in lams.jar) to take Grouping as a parameter, rather than GroupingActivity, so checking in Monitoring changes to match.
