SLING-3021 :  Use service properties for HC meta data and improve JMX registration 

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1515349 13f79535-47bb-0310-9956-ffa450edef68
Add toString() methods

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1515350 13f79535-47bb-0310-9956-ffa450edef68