HDFS-6809. Move Balancer's inner classes MovedBlocks and Matcher as to standalone classes and separates KeyManager from NameNodeConnector.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1616422 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6812. Remove addBlock and replaceBlock from DatanodeDescriptor.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1616426 13f79535-47bb-0310-9956-ffa450edef68