HADOOP-9803. Add a generic type parameter to RetryInvocationHandler.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1509070 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4513. Clarify in the WebHDFS REST API that all JSON respsonses may contain additional properties.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1509075 13f79535-47bb-0310-9956-ffa450edef68