HDFS-6057. DomainSocketWatcher.watcherThread should be marked as a daemon thread (cmccabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1574787 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6058. Fix TestHDFSCLI failures after HADOOP-8691 change. Contributed by Akira Ajisaka and Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1574792 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6061. Allow dfs.datanode.shared.file.descriptor.path to contain multiple entries and fall back when needed (cmccabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1574796 13f79535-47bb-0310-9956-ffa450edef68