MAPREDUCE-5533. Fixed MR speculation code to track any TaskAttempts that aren't heart-beating for a while, so that we can aggressively speculate instead of waiting for task-timeout. Contributed by Xuan Gong.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1529229 13f79535-47bb-0310-9956-ffa450edef68
YARN-1232. Configuration to support multiple RMs (Karthik Kambatla via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1529251 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HDFS-4312-trunk-gd