HDFS-6186. Pause deletion of blocks when the namenode starts up. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594314 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5888. Failed job leaves hung AM after it unregisters (Jason Lowe via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594317 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10583. bin/hadoop key throws NPE with no args and assorted other fixups. (clamb via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594320 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5814. fat jar with *-default.xml may fail when mapreduce.job.classloader=true. Contributed by Gera Shegalov


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594326 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5652. NM Recovery. ShuffleHandler should handle NM restarts. (Jason Lowe via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594329 13f79535-47bb-0310-9956-ffa450edef68