OAK-1133: Observation listener PLUS
Add generic classes and interfaces for event filtering and generation

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1543077 13f79535-47bb-0310-9956-ffa450edef68
OAK-1133: Observation listener PLUS
Add JCR specific filter implementations

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1543079 13f79535-47bb-0310-9956-ffa450edef68