YARN-1049. ContainerExistStatus should define a status for preempted containers. (tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1521037 13f79535-47bb-0310-9956-ffa450edef68
YARN-1144. Unmanaged AMs registering a tracking URI should not be proxy-fied. (tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1521044 13f79535-47bb-0310-9956-ffa450edef68