Updating for 0.23.7 release

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1469560 13f79535-47bb-0310-9956-ffa450edef68
YARN-476. ProcfsBasedProcessTree info message confuses users. Contributed by Sandy Ryza


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1469593 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-0.23' into branch-0.23-gd
Merge remote branch 'origin/branch-0.23-gd' into fb-HADOOP-9016-branch-0.23-gd