add option to redirect moved or non-local volumes

fix https://github.com/chrislusf/seaweedfs/issues/168

go/weed/weed_server/volume_server.go

@@ -22,6 +22,7 @@ type VolumeServer struct {
 
 	needleMapKind     storage.NeedleMapType
 	FixJpgOrientation bool
+	ReadRedirect      bool
 }
 
 func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
@@ -31,13 +32,15 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 	masterNode string, pulseSeconds int,
 	dataCenter string, rack string,
 	whiteList []string,
-	fixJpgOrientation bool) *VolumeServer {
+	fixJpgOrientation bool,
+	readRedirect bool) *VolumeServer {
 	vs := &VolumeServer{
 		pulseSeconds:      pulseSeconds,
 		dataCenter:        dataCenter,
 		rack:              rack,
 		needleMapKind:     needleMapKind,
 		FixJpgOrientation: fixJpgOrientation,
+		ReadRedirect:      readRedirect,
 	}
 	vs.SetMasterNode(masterNode)
 	vs.store = storage.NewStore(port, ip, publicUrl, folders, maxCounts, vs.needleMapKind)