Issue #455 revert tab ordering feature

This relied on JavaFX functionality that appears not to work perfectly
at the moment.

src/ca/mcgill/cs/jetuml/gui/EditorFrame.java

@@ -104,7 +104,7 @@ public EditorFrame(Stage pMainStage, Optional<File> pOpenWith)
 		setTop(menuBar);
 
 		TabPane tabPane = new TabPane();
-		tabPane.setTabDragPolicy(TabPane.TabDragPolicy.REORDER);
+//		tabPane.setTabDragPolicy(TabPane.TabDragPolicy.REORDER); // This JavaFX feature is too buggy to use at the moment see issue #455
 		tabPane.getSelectionModel().selectedItemProperty().addListener((pValue, pOld, pNew) -> setMenuVisibility());
 		setCenter( tabPane );