full message history now in FULL COLOR
generalized Game.map to give it another dimension to hold dungeon_level
Had to change Game.map to a dict.  Added maplist to data.py mapping dungeon_level to level names.
step 1 in generalizing stairs. changed 'stairs' to 'downstairs'. added keypress check for 'upstairs'.
surgery to make fireball spell to create its own fov map to ensure enemies behind walls don't get hit.
in other words: fixed: <cortex> transdimensional fireballs
fixed fireball radius fov
fixed corpses display above items
hooked up 'upstairs' to new function, prev_level().
if player goes up on floor 1, the game ends
if player goes up on another floor, they return the previous floor, but at the same x,y locations from the floor below. same for all objects.
still need to save objects separately on each floor
removed all mapobj and just created a new object in Game called currentmap.
another attempt at generalizing the Game.map.  created def mapname in Global Class Game.