HDFS-4772. Merging change r1495535 from branch-2

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1495539 13f79535-47bb-0310-9956-ffa450edef68
Merge r1495538 from branch-2 to branch-2.1-beta for YARN-827. Need to make Resource arithmetic methods accessible (Jian He via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1495540 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1495577 FIXES: HADOOP-9421. [RPC v9] Convert SASL to use ProtoBuf and provide negotiation capabilities (daryn)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1495585 13f79535-47bb-0310-9956-ffa450edef68