https://issues.apache.org/jira/browse/AMQ-4682 - implement runtimeConfigurationPlugin that will track xml config and react to changes. simple verification via test that adds a new network connector on the fly

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1513871 13f79535-47bb-0310-9956-ffa450edef68