OO-756: check the key of the owner of lockentry instead of user name as the user name can be changed after the user be deleted
OO-753: remove the optimistic locking from SecurityGroupMemebership and make almost all field immutable
OO-749: check if the controller is disposed before updating the business path (with back is possible)
OO-747: in case of a login with no sites, no tabs, place a dummy panel and a gui stack to prevent the red screen
OO-737: hardened the method to prevent an exception in the renderBodyOnLoad (which is probably not usefull)
