svn merge -c 1445456 FIXES: MAPREDUCE-4992. AM hangs in RecoveryService when recovering tasks with speculative attempts. Contributed by Robert Parker


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1445457 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd