HDFS-5365. Merging change r1533283 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1533285 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4511. Cover package org.apache.hadoop.hdfs.tools with unit test (Andrey Klochkov via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1533545 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5365. Merging change r1533574 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1533575 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5457. Add a KeyOnlyTextOutputReader to enable streaming to write out text files without separators (Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1533626 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5587. TestTextOutputFormat fails on JDK7 (jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1533630 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5276. FileSystem.Statistics should use thread-local counters to avoid multi-threaded performance issues on read/write.  (Colin Patrick McCabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1533670 13f79535-47bb-0310-9956-ffa450edef68
YARN-1185. Fixed FileSystemRMStateStore to not leave partial files that prevent subsequent ResourceManager recovery. Contributed by Omkar Vinit Joshi.
svn merge --ignore-ancestry -c 1533803 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1533805 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd
Merge remote branch 'origin/branch-2-gd' into fb-HADOOP-9166-branch-2-gd