MAPREDUCE-4680. Job history cleaner should only check timestamps of files in old enough directories (Robert Kanter via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1536561 13f79535-47bb-0310-9956-ffa450edef68
YARN-1109. Demote NodeManager "Sending out status for container" logs to debug (haosdent via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1536574 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd
Merge remote branch 'origin/branch-2-gd' into fb-YARN-474-branch-2-gd