MAPREDUCE-5900. Changed to the interpret container preemption exit code as a task attempt killing event. Contributed by Mayank Bansal.
svn merge --ignore-ancestry -c 1607512 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1607513 13f79535-47bb-0310-9956-ffa450edef68