HBASE-6104. Require EXEC permission to call coprocessor endpoints

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1553344 13f79535-47bb-0310-9956-ffa450edef68
HBASE-6104. Require EXEC permission to call coprocessor endpoints. Add missing file

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1553347 13f79535-47bb-0310-9956-ffa450edef68