YARN-891. Modified ResourceManager state-store to remember completed applications so that clients can get information about them post RM-restart. Contributed by Jian He.
svn merge --ignore-ancestry -c 1537560 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1537561 13f79535-47bb-0310-9956-ffa450edef68
YARN-1381. Same relaxLocality appears twice in exception message of AMRMClientImpl#checkLocalityRelaxationConflict() (Ted Yu via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1537636 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9898. Set SO_KEEPALIVE on all our sockets. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1537638 13f79535-47bb-0310-9956-ffa450edef68