HDFS-6178. Decommission on standby NN couldn't finish. Contributed by Ming Ma.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1589002 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5852. Prepare MapReduce codebase for JUnit 4.11. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1589006 13f79535-47bb-0310-9956-ffa450edef68