HDFS-5100. TestNamenodeRetryCache fails on Windows due to incorrect cleanup. Contributed by Chuan Liu.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1514573 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5103. TestDirectoryScanner fails on Windows. Contributed by Chuan Liu.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1514576 13f79535-47bb-0310-9956-ffa450edef68