Add some Linux fonts to the stack
Refactored knowledge of tile visibility and terrain grid out of the Screen class
- With this done, it's now feasible (probably) to create a substitute Screen class that displays graphical tiles from a dictionary keyed by character, colour, and inverseness. I'm not going to do that, though.
Better handling of the order in which to draw entities.
Fix some issues of the game ticking when it shouldn't and not ticking when it should.
- Level up menu delayed until game has ticked (because delaying the game until the menu has exited is nontrivial).
- Attempting to disarm traps ticks the game. However, you no longer disarm the trap and open the chest in one turn; you must now disarm the trap before opening the chest.
- Opening a chest does not tick the game, but removing an item from it does.
- Drinking a non-beneficial potion now ticks the game. So does eating food.
- Monsters with inventory (such as thieves) are no longer considered containers by the put command
- Putting doesn't tick the game if you try to put the item in an invalid place
- Getting no longer ticks the game in all situations, for example getting a locked chest or with a full inventory
- Fix to the endgame (changing exit portal colour to indicate repairedness was broken)