Make it clear that you can't mix 2D rendering and the window surface API

Also added functions to query and destroy the window surface so you can switch between modes if you want.

See https://github.com/pygame-community/pygame-ce/issues/2190 for more details.

src/dynapi/SDL2.exports

@@ -868,3 +868,5 @@
 ++'_SDL_ResetHints'.'SDL2.dll'.'SDL_ResetHints'
 ++'_SDL_strcasestr'.'SDL2.dll'.'SDL_strcasestr'
 # ++'_SDL_GDKSuspendComplete'.'SDL2.dll'.'SDL_GDKSuspendComplete'
+++'_SDL_HasWindowSurface'.'SDL2.dll'.'SDL_HasWindowSurface'
+++'_SDL_DestroyWindowSurface'.'SDL2.dll'.'SDL_DestroyWindowSurface'

src/dynapi/SDL_dynapi_overrides.h

@@ -894,3 +894,5 @@
 #define SDL_ResetHints SDL_ResetHints_REAL
 #define SDL_strcasestr SDL_strcasestr_REAL
 #define SDL_GDKSuspendComplete SDL_GDKSuspendComplete_REAL
+#define SDL_HasWindowSurface SDL_HasWindowSurface_REAL
+#define SDL_DestroyWindowSurface SDL_DestroyWindowSurface_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -979,3 +979,5 @@ SDL_DYNAPI_PROC(char*,SDL_strcasestr,(const char *a, const char *b),(a,b),return
 #if defined(__GDK__)
 SDL_DYNAPI_PROC(void,SDL_GDKSuspendComplete,(void),(),)
 #endif
+SDL_DYNAPI_PROC(SDL_bool,SDL_HasWindowSurface,(SDL_Window *a),(a),return)
+SDL_DYNAPI_PROC(int,SDL_DestroyWindowSurface,(SDL_Window *a),(a),return)