actually delete the node from the tree

action.go

@@ -98,6 +98,7 @@ func (me *TreeInfo) doAction(a widget.Action) {
 	case widget.Delete:
 		me.Hide(n)
 		log.Info("tree: todo: remove child from parent")
+		n.DeleteNode()
 		// now remove the child from the parent
 	default:
 		log.Log(TREEWARN, "tree.Action() unknown action", a.ActionType, "on wId", a.WidgetId)