SAM-2279: Students lose data if they click any button/link after due date (with no late submissions) or retract date passed

git-svn-id: https://source.sakaiproject.org/svn/sam/trunk@271441 66ffb92e-73f9-0310-93c1-f5514f145a0a
SAM-2281 NPE for ResourceLoader


git-svn-id: https://source.sakaiproject.org/svn/sam/trunk@305954 66ffb92e-73f9-0310-93c1-f5514f145a0a
SAM-1943: Support for Extended Matching Item (R-type) MCQs

git-svn-id: https://source.sakaiproject.org/svn/sam/trunk@305964 66ffb92e-73f9-0310-93c1-f5514f145a0a