HADOOP-10710. hadoop.auth cookie is not properly constructed according to RFC2109. (Juan Yu via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1606925 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6591. Merging change r1606927 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1606931 13f79535-47bb-0310-9956-ffa450edef68