SAK-28051 Bug when releasing grades from assignments for a group submission that is linked to a gradebook item

git-svn-id: https://source.sakaiproject.org/svn/assignment/trunk@315603 66ffb92e-73f9-0310-93c1-f5514f145a0a
SAK-25944 Assignment associated to grade item: student's grade cannot be changed in assignment tool

git-svn-id: https://source.sakaiproject.org/svn/assignment/trunk@315604 66ffb92e-73f9-0310-93c1-f5514f145a0a