SAK-26060 removed unused caching code which was incompatible with JSR-170

git-svn-id: https://source.sakaiproject.org/svn/message/trunk@307897 66ffb92e-73f9-0310-93c1-f5514f145a0a
SAK-26060 removed unused cache refresher code (separate, in case it is needed later)

git-svn-id: https://source.sakaiproject.org/svn/message/trunk@307899 66ffb92e-73f9-0310-93c1-f5514f145a0a