HADOOP-11070. Create MiniKMS for testing. (tucu)
HADOOP-11069. KMSClientProvider should use getAuthenticationMethod() to determine if in proxyuser mode or not. (tucu)
HDFS-6986. DistributedFileSystem must get delegation tokens from configured KeyProvider. (zhz via tucu)
HDFS-6940. Refactoring to allow ConsensusNode implementation.
Contributed by Konstantin Shvachko.
Merge remote-tracking branch 'apache-commit/trunk' into HDFS-6581