Currently we don't use oscache in JIRA anymore. We should remove it from project.xml.

From what I can tell, we also need to:

• Find and remove all usages of CacheUtils.flush() and CacheUtils.flushAll()
• Remove oscache.tld
• Remove oscache.properties

Also, in core - we should check what else uses oscache, and remove them also. Then remove the dependency from oscore, and rev it.