Merge -c 1476463 from branch-1 to branch-1.2 to fix MAPREDUCE-5158. Cleanup job-submission related files on HDFS during JobTracker restart for jobs which set mapreduce.job.restart.recover to false to indicate they don't want to be recovered. Contributed by Mayank Bansal.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2@1476464 13f79535-47bb-0310-9956-ffa450edef68