Fixes to DEV29-30 schema migration after rollout
Changed version back to 1.0-SNAPSHOT after DEV30
Merged DEV29->30 into M4->M5 schema migration
Moved flash message stuff to GlobalRouter
Continued filling in LTI instructor MVC layer
Improved assessment deletion.

This was not deleting candidate data from the filesystem.
Also added a count of the number of open UserRole.CANDIDATE
sessions for a given Assessment, to help decide whether it should
be deleted.
Continued on LTI instructor MVC