MAPREDUCE-5746. Job diagnostics can implicate wrong task for a failed job. (Jason Lowe via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1567666 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5879. Some TestHftpFileSystem tests do not close streams. Contributed by Gera Shegalov.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1567704 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5810. Unify mmap cache and short-circuit file descriptor cache (cmccabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1567720 13f79535-47bb-0310-9956-ffa450edef68