functions and a couple of variables, now each one exports a single
structure containing a load of function pointers and said variables.
This should make it easy to support platforms on which it's sensible
to compile all the puzzles into a single monolithic application. The
two existing platforms are still one-binary-per-game.
[originally from svn r5126]
argument `dir' which tells them whether this redraw is due to an undo, rather
than have them second-guess it from game state.
Note that none of the actual games yet take advantage of this; so it hasn't
been tested in anger (although it has been inspected by debugging).
[originally from svn r4469]
