Merge -c 1477900 from branch-1 to branch-1.2 to fix MAPREDUCE-5154. Ensure job delegation token renewal is cancelled after job staging directory is deleted. Contributed by Sandy Ryza & Arun C. Murthy.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2@1477901 13f79535-47bb-0310-9956-ffa450edef68