Bug 67811 Need support for adding separators to the help menu
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/WorkbenchActionBuilder.java
menu.add(new GroupMarker(IWorkbenchActionConstants.OPEN_EXT));
        menu.add(new Separator());
        menu.add(buildAllAction);
        menu.add(buildProjectAction);
        addWorkingSetBuildActions(menu);
        menu.add(cleanAction);
        menu.add(toggleAutoBuildAction);
        menu.add(new GroupMarker(IWorkbenchActionConstants.BUILD_EXT));
        menu.add(new Separator());
        menu.add(new GroupMarker(IWorkbenchActionConstants.MB_ADDITIONS));
        menu.add(new GroupMarker(IWorkbenchActionConstants.PROJ_END));
        menu.add(new Separator());
        menu.add(projectPropertyDialogAction);
        return menu;
    }
    /**
     * Creates and returns the Window menu.
     */
    private MenuManager createWindowMenu() {
        MenuManager menu = new MenuManager(
                IDEWorkbenchMessages.getString("Workbench.window"), IWorkbenchActionConstants.M_WINDOW); 
        IWorkbenchAction action = ActionFactory.OPEN_NEW_WINDOW
                .create(getWindow());
        action.setText(IDEWorkbenchMessages
                .getString("Workbench.openNewWindow")); 
        menu.add(action);
        menu.add(new Separator());
        addPerspectiveActions(menu);
        menu.add(new Separator());
        addKeyboardShortcuts(menu);