svn merge -c 1551285 FIXES: MAPREDUCE-5623. TestJobCleanup fails because of RejectedExecutionException and NPE. Contributed by Jason Lowe


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1551287 13f79535-47bb-0310-9956-ffa450edef68