Major:

change replication_type to ReplicaPlacement, hopefully cleaner code
works for 9 possible ReplicaPlacement
xyz
x : number of copies on other data centers
y : number of copies on other racks
z : number of copies on current rack
x y z each can be 0,1,2

Minor:
weed server "-mdir" default to "-dir" if empty

go/operation/list_masters.go

@@ -23,5 +23,9 @@ func ListMasters(server string) ([]string, error) {
 	if err != nil {
 		return nil, err
 	}
-	return ret.Peers, nil
+	masters := ret.Peers
+	if ret.IsLeader {
+		masters = append(masters, ret.Leader)
+	}
+	return masters, nil
 }