DEBUG: a command line parameter to enable cheat mode.
ALT-B: change a building type by one.
ALT-C: change a character.
ALT-F: change a building type by ten.
ALT-K: destroys a random enemy stronghold.
ALT-L: increases character level (press repeatedly then select
character to apply).
ALT-P: promotes character.
ALT-Z: destroys all enemy units on the screen.
