SLING-3470 - Improved coverage of agent and importer resources

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1579646 13f79535-47bb-0310-9956-ffa450edef68
SLING-3471 - added IT for agent commands

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1579647 13f79535-47bb-0310-9956-ffa450edef68