hero_seq

'moves' is actually turns and there hasn't been any straightforward
way to track actual hero moves.  Add hero_seq for that.  It isn't a
counter but is distinct each time the hero makes a move.  I wanted
it for curses ^P support but so far use it for checking stethoscope
usage and for shopkeeper behavior when items in a shop are broken by
the hero.

Increment EDITLEVEL due to change in save file contents.

src/apply.c

@@ -319,10 +319,8 @@ use_stethoscope(struct obj *obj)
     if (!getdir((char *) 0))
         return 0;
 
-    res = (g.moves == g.context.stethoscope_move)
-          && (g.youmonst.movement == g.context.stethoscope_movement);
-    g.context.stethoscope_move = g.moves;
-    g.context.stethoscope_movement = g.youmonst.movement;
+    res = (g.hero_seq == g.context.stethoscope_seq);
+    g.context.stethoscope_seq = g.hero_seq;
 
     g.bhitpos.x = u.ux, g.bhitpos.y = u.uy; /* tentative, reset below */
     g.notonhead = u.uswallow;