nodeview: update positions correctly

app/widget/nodeview/nodeviewscene.h

@@ -106,6 +106,9 @@ public slots:
    */
   void SetEdgesAreCurved(bool curved);
 
+signals:
+  void NodePositionChanged(NodeViewItem *node, const QPointF &pos);
+
 private:
   static int DetermineWeight(Node* n);
 
@@ -127,6 +130,8 @@ private slots:
    */
   void NodeAppearanceChanged();
 
+  void NodeItemPositionChanged(const QPointF &pos);
+
 };
 
 }