Move keyboard layout logic into the .kv file.

I wish I knew a better way to do this. What’s in the .kv file now is
gross WET code but it saves having to deal with binding everything up
in the Python to change the color of a key. And a keyboard layout is
really layout logic, and is pretty static.
Remove debug print.
Remove debug print.
Highlight the first note of a Beastie attack.

I don’t like how this is done, but it works. Creatures shouldn’t have
to know about the screen they’re on. It would probably suffice to link
to the Keyboard instead, or even have Beasties dispatch events to the
party they’re in instead of the Screen instance. Or both.