Grilles and rods.

Grilles no longer return more rods than they were created from when destroyed (by method other than wirecutters).
Rods are now acquired from and returned to a pool.
Also adds a pre-broken grille for mapping, avoids the case where one might be able to destroy the same grille twice.

code/game/objects/structures/window.dm

@@ -88,11 +88,11 @@
 		index = 0
 		while(index < 2)
 			new shardtype(loc)
-			if(reinf) new /obj/item/stack/rods(loc)
+			if(reinf) PoolOrNew(/obj/item/stack/rods, loc)
 			index++
 	else
 		new shardtype(loc)
-		if(reinf) new /obj/item/stack/rods(loc)
+		if(reinf) PoolOrNew(/obj/item/stack/rods, loc)
 	qdel(src)
 	return