wire up the quit button

windows/WinUI/ToolbarItem.xaml

@@ -47,7 +47,8 @@
                             <MenuItem Header="Preferences..."
                                       Click="ToolbarItem_PreferencesClicked"/>
                             <Separator/>
-                            <MenuItem Header="Quit"/>
+                            <MenuItem Header="Quit"
+                                      Click="ToolbarItem_QuitClicked"/>
                             
                         </CompositeCollection>
                     </ContextMenu.ItemsSource>

windows/WinUI/ToolbarItem.xaml.cs

@@ -173,6 +173,13 @@ namespace WinUI
             prefsView = null;
         }
 
+        private void ToolbarItem_QuitClicked(object sender, System.EventArgs e)
+        {
+            this.Close();
+            Application.Current.Shutdown();
+            Environment.Exit(0);
+        }
+
         private void ToolbarItem_NetworkClicked(object sender, System.Windows.RoutedEventArgs e)
         {
             if(sender.GetType() == typeof(MenuItem))