YARN-1033. Expose RM active/standby state to Web UI and REST API (kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1557181 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10178. Configuration deprecation always emit "deprecated" warnings when a new key is used. Contributed by Shanyu Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1557236 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5756. hadoopRzOptionsSetByteBufferPool does not accept NULL argument, contrary to docs. Contributed by Colin Patrick McCabe.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1557244 13f79535-47bb-0310-9956-ffa450edef68
YARN-1574. RMDispatcher should be reset on transition to standby. (Xuan Gong via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1557248 13f79535-47bb-0310-9956-ffa450edef68