OAK-482 Group members stored in a rep:members tree
- revert from previous commit: println for diagnosing build failure on Buildbot
- Temporary disable using files for reporting test failures

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1545188 13f79535-47bb-0310-9956-ffa450edef68