Use game_set_size() to set up the temporary drawstate in

game_print(), wherever feasible. This fixes a specific bug in Loopy
(James H's new field ds->linewidth wasn't being set up, leading to
corrupted print output), but I've made the change in all affected
files because it also seems like a generally good idea to encourage
it for future games, to prevent other problems of this type.

There is one slight snag, which is that Map _can't_ do this because
its game_set_size() also initialises a blitter. I could fix this by
abstracting the common parts of Map's game_set_size() out into a
subfunction called by game_set_size() and also called directly by
game_print(); alternatively, I could introduce a means of
determining whether a `drawing *' was for screen or printing use.
Not sure which yet.

[originally from svn r6340]

slant.c

@@ -2001,7 +2001,7 @@ static void game_print(drawing *dr, game_state *state, int tilesize)
 
     /* Ick: fake up `ds->tilesize' for macro expansion purposes */
     game_drawstate ads, *ds = &ads;
-    ads.tilesize = tilesize;
+    game_set_size(dr, ds, NULL, tilesize);
 
     /*
      * Border.