options: ascii_map vs tiled_map

options: ascii_map vs tiled_map

X11 supports both ascii map and tiled map and is able to switch back
and forth during play.  'O' shows both of them as boolean options, but
toggling ascii_map did nothing since tiled_map retained whatever value
it had at the time.  For core options handling, make toggling either
ascii_map or tiled_map also set the other one to the opposite value,
so ascii on forces tiled off and vice versa.