Multiple uiwindow in sdl

if you want to keep objc code and sdl code separated we can create a
first uiwindow in which we put our objc frontend and another uiwindow
created by sdl.
the problem is that if you call multiple times the sdl code, you
obtain multiple uiwindow-s and this is a very bad memory leak.

so i’m proposing this change to SDL_uikiwindow.m (lines 138 on)

UIWindow *uiwindow;

UIWindow *exisitingWin = [[[UIApplication sharedApplication]

windows] lastObject];
if ([exisitingWin isKeyWindow]) {
uiwindow = [UIWindow alloc];
if (window->flags & SDL_WINDOW_BORDERLESS)
uiwindow = [uiwindow initWithFrame:[uiscreen bounds]];
uiwindow = [uiwindow initWithFrame:[uiscreen applicationFrame]];

    if (SDL_UIKit_supports_multiple_displays) {
        [uiwindow setScreen:uiscreen];
} else
    uiwindow = exisitingWin;

in this way only 2 uiwindows are created; if the first is the main
objc window then the sdl one is created, otherwise it just reuses the
old one.
truth is it would be nice that the sdl’s uiwindows would be released
when sdl code ends, but this is a nice and quick workaround

any thoughts on this?