svn merge -c 1487647 from trunk for HDFS-4846. Clean up snapshot CLI commands output stacktrace for invalid arguments.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488093 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1487655 from trunk for HDFS-4857. Snapshot.Root and AbstractINodeDiff#snapshotINode should not be put into INodeMap when loading FSImage.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488094 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1487698 from trunk for HDFS-4863. The root directory should be added to the snapshottable directory list while loading fsimage.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488096 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1487942 from trunk for HDFS-4848. copyFromLocal and renaming a file to ".snapshot" should output hat ".snapshot" is a reserved name.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488097 13f79535-47bb-0310-9956-ffa450edef68