Show a simple message box

Property definitions

sdl2 $ SDL :: show_simple_message_box
	# Show a simple message box
	fun show_simple_message_box(level: SDLMessageBoxFlags, title, content: CString) `{
		SDL_ShowSimpleMessageBox(level, title, content, NULL);
	`}
lib/sdl2/sdl2_base.nit:67,2--70,3