Prevent NPE in Guard ACLConfigurationParser when an argument is null

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1546593 13f79535-47bb-0310-9956-ffa450edef68
Enable JMX RBAC support in itests

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1546594 13f79535-47bb-0310-9956-ffa450edef68
Add an itest on instanceRename operation via InstanceMBean

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1546595 13f79535-47bb-0310-9956-ffa450edef68