OAK-1317 OutOfMemoryError in org.apache.jackrabbit.mk.json.JsopBuilder.toString

- disabling test case

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1556997 13f79535-47bb-0310-9956-ffa450edef68
OAK-1311 Permission Cache causes non-deterministic access control test failures

- replaced timestamp with mod counter

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1556998 13f79535-47bb-0310-9956-ffa450edef68