merge -c 1441668 from trunk to branch-2 to fix YARN-372. Move InlineDispatcher from hadoop-yarn-server-resourcemanager to hadoop-yarn-common. Contributed by Siddharth Seth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1441669 13f79535-47bb-0310-9956-ffa450edef68
merge MAPREDUCE-4971 from trunk. Minor extensibility enhancements to Counters & FileOutputFormat. Contributed by Arun C Murthy


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1441672 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4452. getAdditionalBlock() can create multiple blocks if the client times out and retries. Contributed by Konstantin Shvachko.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1441682 13f79535-47bb-0310-9956-ffa450edef68