MAPREDUCE-5806. Fixed a bug in MRAppMaster so as to enable users to properly override HADOOP_ROOT_LOGGER or HADOOP_CLIENT_OPTS. Contributed by Varun Vasudev.
svn merge --ignore-ancestry -c 1580100 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1580102 13f79535-47bb-0310-9956-ffa450edef68