YARN-50. Implement renewal / cancellation of Delegation Tokens(Siddharth Seth via tgraves)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1429104 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-4894. Renewal / cancellation of JobHistory tokens (Siddharth Seth via tgraves)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1429105 13f79535-47bb-0310-9956-ffa450edef68