worn gear after polymorph alignment change [1 of 2] (trunk only)

Make polymorphing or changing alignment perform a touch check (as is
done when catching lycanthropy) on wielded weapon(s) to see whether the
hero can still use them in his new form.  Part [2 of 2] will update
retouch_equipment() to check all items in use rather than just weapon(s).
(A comment or two in part 1 already refers to expected behavior of part 2.)

src/mhitu.c

@@ -1232,8 +1232,7 @@ dopois:
 		    You_feel("feverish.");
 		    exercise(A_CON, FALSE);
 		    u.ulycn = monsndx(mdat);
-		    if (u.twoweap) (void)retouch_object(&uswapwep, TRUE);
-		    if (uwep) (void)retouch_object(&uwep, TRUE);
+		    retouch_equipment(2);
 		}
 		break;
 	    case AD_SGLD: