Fix for mask errors with camera/scissor tool

Detail:
  Longstanding bug where use of the camera or scissor tool in Export mode with 'new' 1bpp mask sprites didn't work. Change to use SpriteExtend's scaled mask op.
  Ref: https://www.riscosopen.org/tracker/tickets/481
Admin:
  Submission for Paint bounty.

c/Tools

@@ -1686,9 +1686,9 @@ static void scissorpaint_null (main_window *window, wimp_mousestr *mpos)
           os_swi2 (OS_SetColour, 1 << 4, 0);  /* set empty gcol */
           bbc_clg ();                         /* clear it all out */
           os_swi2 (OS_SetColour, 1 << 4, -1); /* set solid gcol */
-          error = sprite_put_mask_given (sprite->file->spritearea,
+          error = sprite_put_mask_scaled (sprite->file->spritearea,
               &ssid, -tools_pixel_to_point_x(&window->data->sprite, sprite->toolspace [1]),
-                     -tools_pixel_to_point_y(&window->data->sprite, sprite->toolspace [2]));
+                     -tools_pixel_to_point_y(&window->data->sprite, sprite->toolspace [2]), 0);
           sprwindow_swap_output_to_screen ();
           wimpt_noerr (error);
         }