YARN-269. Resource Manager not logging the health_check_script result when taking it out. Contributed by Jason Lowe

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1451343 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9336. Allow UGI of current connection to be queried. Contributed by Daryn Sharp.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1451383 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-0.23' into branch-0.23-gd