iron balls (R676)

iron balls (R676)
Well, this proved rather annoying.  Problems included:
-- the solid rock problem that was noticed
-- teleporting to a spot two spaces away but on the other side of solid rock
could also leave the chain in solid rock
-- in one place I said chainx instead of ballx, which could cause problems with
teleporting
-- the teleport code moved the player before moving the ball, violating the
assumption that the player hasn't been moved yet (which only caused problems
after I added the solid rock fix).

Ball movement still isn't quite right, though the cases are really rare.  I
may fix them later.