MAPREDUCE-5476. Changed MR AM recovery code to cleanup staging-directory only after unregistering from the RM. Contributed by Jian He.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1516660 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5124. DelegationTokenSecretManager#retrievePassword can cause deadlock in NameNode. Contributed by Daryn Sharp.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1516671 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HDFS-4312-trunk-gd