KNL-1060 Invalidate grants cache when editing special realms.

This fixes the bug where when a special realm is edited (eg !site.helper) the grants cache wasn't getting invalidated.

git-svn-id: https://source.sakaiproject.org/svn/kernel/trunk@123045 66ffb92e-73f9-0310-93c1-f5514f145a0a
KNL-1043 Attempted to manage this with AOP but that doesn't look like it will work, this is just to document that effort so it is not lost to history

git-svn-id: https://source.sakaiproject.org/svn/kernel/trunk@123049 66ffb92e-73f9-0310-93c1-f5514f145a0a