HADOOP-9451. Fault single-layer config if node group topology is enabled. (Junping Du via llu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1464301 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4665. Move TestNetworkTopologyWithNodeGroup to common. (Junping Du via llu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1464303 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-YAHOO-234-trunk-gd