YARN-1986. In Fifo Scheduler, node heartbeat in between creating app and attempt causes NPE (Hong Zhiguo via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594476 13f79535-47bb-0310-9956-ffa450edef68
YARN-2042. String shouldn't be compared using == in QueuePlacementRule#NestedUserQueue#getQueueForApp (Chen He via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594482 13f79535-47bb-0310-9956-ffa450edef68