OAK-51 : Access Control Management (wip)

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1482930 13f79535-47bb-0310-9956-ffa450edef68
OAK-50 : Implement User Management  (minor improvement)


git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1482931 13f79535-47bb-0310-9956-ffa450edef68