HADOOP-9043. disallow in winutils creating symlinks with forwards slashes. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1-win@1478581 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4782. Backport edit log corruption toleration. Contributed by Chris Nauroth


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1-win@1478622 13f79535-47bb-0310-9956-ffa450edef68