OAK-527: permissions

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1478811 13f79535-47bb-0310-9956-ffa450edef68
OAK-774 : Calculate readstatus upon initialization of permission provider (test patch provided by antonio sanso)

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1478812 13f79535-47bb-0310-9956-ffa450edef68