HADOOP-10171. TestRPC fails intermittently on jkd7 (Mit Desai via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1552024 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5687. Correcting the previous commit by ushing the right patch.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1552069 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10164. Allow UGI to login with a known Subject (bobby)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1552104 13f79535-47bb-0310-9956-ffa450edef68