MAPREDUCE-5364. Committed to branch-1.2 also.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1499900 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5375. Use short name for renewing delegation tokens. Contributed by Venkat Ranganathan.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1499902 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5351. Addedndum patch to ensure we don't incorrectly close wrong filesystems. Contributed by Sandy Ryza.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1499904 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5368. Reduce memory footprint of JobTracker by using non-default values for hash-tables to store Locality and Avataar for TaskAttempts. Contributed by zhaoyunjiong.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1499906 13f79535-47bb-0310-9956-ffa450edef68