OAK-1133: Observation listener PLUS
Promote ConstantFilter to top level class

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1546105 13f79535-47bb-0310-9956-ffa450edef68
OAK-1133: Observation listener PLUS
More exact test expectations

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1546106 13f79535-47bb-0310-9956-ffa450edef68