HDFS-4583. TestNodeCount fails. Contributed by Ivan Mitic.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1456052 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4582. TestHostsFiles fails on Windows. Contributed by Ivan Mitic.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1456060 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4591. HA clients can fail to fail over while Standby NN is performing long checkpoint. Contributed by Aaron T. Myers.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1456107 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HADOOP-9291-trunk-gd