HDFS-4807. createSocketForPipeline() should not include timeout extension on connect. Contributed by Cristina Abad.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1485864 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4714. Log short messages in Namenode RPC server for exceptions meant for clients. Contributed by Kihwal Lee.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1485884 13f79535-47bb-0310-9956-ffa450edef68
YARN-548. Add tests for YarnUncaughtExceptionHandler (Vadim Bondarev via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1485885 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-0.23' into branch-0.23-gd
Merge remote branch 'origin/branch-0.23-gd' into fb-xxx-hadoop-auth-kerberos-realm-branch-0.23-gd