Unbitrot Minesweeper

[Chromatic]

Here's a patch that gets the Minesweeper examine running again. It's not
*correct*, in that the field-drawing math appears to do the wrong thing, but
I couldn't find the easy way to fix that. Maths is hard.

I cleaned up just enough of the code to get it to do the wrong thing without
crashing. That's progress, right?

For what it's worth, the cleanup process included finding and fixing a few
potentially buggy situations. That seems valuable; the changes to PIR have
been improvements for the most part.

(The object initialization and parameter passing style is still difficult
enough that I really want to port the Perl 6 metaclass stuff. Any
objections?)

-- c

$ diffstat fix_minesweeper.patch
examples/sdl/anim_image.pir | 1
examples/sdl/minesweeper/field.pir | 231
++++++++++---------------------
examples/sdl/minesweeper/mines.pir | 59 +++----
runtime/parrot/library/SDL/Button.pir | 39 ++---
runtime/parrot/library/SDL/LCD.pir | 37 +---
runtime/parrot/library/SDL/Rect.pir | 4
runtime/parrot/library/SDL/StopWatch.pir | 10 -
7 files changed, 145 insertions(+), 236 deletions(-)