HBASE-10207 ZKVisibilityLabelWatcher : Populate the labels cache on startup

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1552488 13f79535-47bb-0310-9956-ffa450edef68
HBASE-10173. Need HFile version check in security coprocessors

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1552503 13f79535-47bb-0310-9956-ffa450edef68