u.utraptype, TT_BEARTRAP

Add 'FIXME' fix by entrez to change TT_BEARTRAP to non-zero.

Increments EDITLEVEL, invalidating existing save and bones files.

src/hack.c

@@ -1510,6 +1510,9 @@ trapmove(int x, int y,       /* targetted destination, <u.ux+u.dx,u.uy+u.dy> */
                 buried_ball_to_punishment();
         }
         break;
+    case TT_NONE:
+        impossible("trapmove: trapped in nothing?");
+        break;
     default:
         impossible("trapmove: stuck in unknown trap? (%d)",
                    (int) u.utraptype);

src/trap.c

@@ -902,12 +902,7 @@ set_utrap(unsigned int tim, unsigned int typ)
         g.context.botl = TRUE;
 
     u.utrap = tim;
-    /* FIXME:
-     * utraptype==0 is bear trap rather than 'none'; we probably ought
-     * to change that but can't do so until save file compatability is
-     * able to be broken.
-     */
-    u.utraptype = tim ? typ : 0;
+    u.utraptype = tim ? typ : TT_NONE;
 
     float_vs_flight(); /* maybe block Lev and/or Fly */
 }