OAK-71 Logging

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1464581 13f79535-47bb-0310-9956-ffa450edef68
OAK-741 Better toString() methods

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1464583 13f79535-47bb-0310-9956-ffa450edef68