svn merge -c 1582856 from trunk for HDFS-6168. Remove a deprecated constructor and the deprecated methods reportChecksumFailure, getDelegationToken(Text), renewDelegationToken and cancelDelegationToken from DistributedFileSystem.  


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1582857 13f79535-47bb-0310-9956-ffa450edef68