HADOOP-10588. Workaround for jetty6 acceptor startup issue. Contributed by Kihwal Lee.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1595051 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6361. Merging change r1595050 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1595053 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5683. Better audit log messages for caching operations. Contributed by Abhiraj Butala.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1595057 13f79535-47bb-0310-9956-ffa450edef68