SDL_Surface refcount: destination surface keep track of surfaces

that are mapped to it and automatically invalidate them when it is freed

- refcount is kept so that an external application can still create a reference
to SDL_Surface.

- lock_data was un-used and is now renamed and used as a list keep track of the blitmap

src/video/SDL_surface.c

@@ -1328,6 +1328,8 @@ SDL_FreeSurface(SDL_Surface * surface)
     }
     SDL_InvalidateMap(surface->map);
 
+    SDL_InvalidateAllBlitMap(surface);
+
     if (--surface->refcount > 0) {
         return;
     }