directory structure change to work with glide

glide has its own requirements. My previous workaround caused me some
code checkin errors. Need to fix this.

weed/topology/topology_map.go

@@ -0,0 +1,53 @@
+package topology
+
+func (t *Topology) ToMap() interface{} {
+	m := make(map[string]interface{})
+	m["Max"] = t.GetMaxVolumeCount()
+	m["Free"] = t.FreeSpace()
+	var dcs []interface{}
+	for _, c := range t.Children() {
+		dc := c.(*DataCenter)
+		dcs = append(dcs, dc.ToMap())
+	}
+	m["DataCenters"] = dcs
+	var layouts []interface{}
+	for _, col := range t.collectionMap.Items() {
+		c := col.(*Collection)
+		for _, layout := range c.storageType2VolumeLayout.Items() {
+			if layout != nil {
+				tmp := layout.(*VolumeLayout).ToMap()
+				tmp["collection"] = c.Name
+				layouts = append(layouts, tmp)
+			}
+		}
+	}
+	m["layouts"] = layouts
+	return m
+}
+
+func (t *Topology) ToVolumeMap() interface{} {
+	m := make(map[string]interface{})
+	m["Max"] = t.GetMaxVolumeCount()
+	m["Free"] = t.FreeSpace()
+	dcs := make(map[NodeId]interface{})
+	for _, c := range t.Children() {
+		dc := c.(*DataCenter)
+		racks := make(map[NodeId]interface{})
+		for _, r := range dc.Children() {
+			rack := r.(*Rack)
+			dataNodes := make(map[NodeId]interface{})
+			for _, d := range rack.Children() {
+				dn := d.(*DataNode)
+				var volumes []interface{}
+				for _, v := range dn.GetVolumes() {
+					volumes = append(volumes, v)
+				}
+				dataNodes[d.Id()] = volumes
+			}
+			racks[r.Id()] = dataNodes
+		}
+		dcs[dc.Id()] = racks
+	}
+	m["DataCenters"] = dcs
+	return m
+}