svn merge -c 1542054 merging from trunk to branch-2 to fix HDFS-5438. Flaws in block report processing can cause data loss.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1542057 13f79535-47bb-0310-9956-ffa450edef68
YARN-1392. Allow sophisticated app-to-queue placement policies in the Fair Scheduler (Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1542108 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1542111 FIXES: HADOOP-9955. RPC idle connection closing is extremely inefficient (daryn)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1542112 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd
Merge remote branch 'origin/branch-2-gd' into fb-MAPREDUCE-4884-branch-2-gd