HDFS-4351.  In BlockPlacementPolicyDefault.chooseTarget(..), numOfReplicas needs to be updated when avoiding stale nodes.  Contributed by Andrew Wang


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1429653 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'trunk' of github.com:griddynamics/yhadoop-common into trunk-gd
Merge branch 'trunk-gd' of github.com:griddynamics/yhadoop-common into fb-YAHOO-123-trunk-gd