Allow the cursor to be force disabled.

OpenRA.Game/Game.cs

@@ -39,6 +39,7 @@ namespace OpenRA
 		public static ModData ModData;
 		public static Settings Settings;
 		public static ICursor Cursor;
+		public static bool HideCursor;
 		static WorldRenderer worldRenderer;
 
 		internal static OrderManager OrderManager;
@@ -658,11 +659,16 @@ namespace OpenRA
 					Ui.Draw();
 
 					if (ModData != null && ModData.CursorProvider != null)
+					{
+						if (HideCursor)
+							Cursor.SetCursor(null);
+						else
 						{
 							Cursor.SetCursor(Ui.Root.GetCursorOuter(Viewport.LastMousePos) ?? "default");
 							Cursor.Render(Renderer);
 						}
 					}
+				}
 
 				using (new PerfSample("render_flip"))
 					Renderer.EndFrame(new DefaultInputHandler(OrderManager.World));