Eye Candy and Highscores

The game now contains Highscores.

You can have five daily entries and five all-time entries that are saved to disk.

Besides that, I added a curtain effect when the dungeon is entered.

And some convenience things behind the scenes, so small that I tend to forget about them.
Like, clearing the keyboard buffer in meaningful places or flow of menus (restart, main menu, etc).

Still not done, but still fun to work on :-)