hangups with temp gold in inventory

- Implement Michael's suggestion of marking temp gold put in inventory
so it can be cleaned up during restore.

src/do.c

@@ -614,6 +614,7 @@ int retry;
 	/* Hack: gold is not in the inventory, so make a gold object
 	   and put it at the head of the inventory list. */
 	u_gold = mkgoldobj(u.ugold);	/* removes from u.ugold */
+	u_gold->in_use = TRUE;
 	u.ugold = u_gold->quan;		/* put the gold back */
 	assigninvlet(u_gold);		/* might end up as NOINVSYM */
 	u_gold->nobj = invent;
@@ -686,6 +687,7 @@ int retry;
 	/* didn't drop [all of] it */
 	u_gold = invent;
 	invent = u_gold->nobj;
+	u_gold->in_use = FALSE;
 	dealloc_obj(u_gold);
 	update_inventory();
     }