Merge -r 1464129:1464130 from trunk to branch-2. Fixes: YARN-381. Improve fair scheduler docs. Contributed by Sandy Ryza.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1464131 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5088. MR Client gets an renewer token exception while Oozie is submitting a job (daryn)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1464147 13f79535-47bb-0310-9956-ffa450edef68