YARN-1167. Fixed Distributed Shell to not incorrectly show empty hostname on RM UI. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1529376 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1529379 13f79535-47bb-0310-9956-ffa450edef68
YARN-1254. Fixed NodeManager to not pollute container's credentials. Contributed by Omkar Vinit Joshi.
svn merge --ignore-ancestry -c 1529382 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1529384 13f79535-47bb-0310-9956-ffa450edef68