mnk-5575, mnk-5514 fix

git-svn-id: http://svn.terracotta.org/svn/ehcache@8214 b9324663-ca0f-0410-8574-be9b3887307d
mnk-5575, mnk-5514, merge 8814 in 2.5.x

git-svn-id: http://svn.terracotta.org/svn/ehcache@8215 b9324663-ca0f-0410-8574-be9b3887307d
WebSession Agent : refactoring the AgentService so that it is part of management-core instead of management-ehcache-impl

git-svn-id: http://svn.terracotta.org/svn/ehcache@8216 b9324663-ca0f-0410-8574-be9b3887307d