svn merge -c 1552711 merging from trunk to branch-2 to fix HDFS-5681. renewLease should not hold fsn write lock.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1552713 13f79535-47bb-0310-9956-ffa450edef68
YARN-1180. Update capacity scheduler docs to include types on the configs (Chen He via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1552789 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5692. Add explicit diagnostics when a task attempt is killed due to speculative execution (Gera Shegalov via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1552799 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5691. Merge 1552802 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1552803 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5550. Task Status message (reporter.setStatus) not shown in UI with Hadoop 2.0 (Gera Shegalov via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1552809 13f79535-47bb-0310-9956-ffa450edef68