2) Optimization - removed bottleneck in cluster - removed counter of sessions from cache. Calculated now on demand.
3) Fixed counter of authenticated session to not decrement when non-authenticated session is removed. JM-1095

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@8663 b35dd754-fafc-0310-a699-88a17e54d16e