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/turfs/simulated/floor_types.dm

@@ -64,7 +64,7 @@
 		user << "\blue Removing rods..."
 		playsound(src, 'sound/items/Ratchet.ogg', 80, 1)
 		if(do_after(user, 30))
-			new /obj/item/stack/rods(src, 2)
+			PoolOrNew(/obj/item/stack/rods, list(loc, 2))
 			ChangeTurf(/turf/simulated/floor)
 			var/turf/simulated/floor/F = src
 			F.make_plating()

code/game/turfs/simulated/walls_reinforced.dm

@@ -98,7 +98,7 @@
 				playsound(src, 'sound/items/Wirecutter.ogg', 100, 1)
 				src.d_state = 1
 				src.icon_state = "r_wall-1"
-				new /obj/item/stack/rods( src )
+				PoolOrNew(/obj/item/stack/rods, src)
 				user << "<span class='notice'>You cut the outer grille.</span>"
 				return
 
@@ -206,7 +206,7 @@
 					if( d_state == 5 && user.loc == T && user.get_active_hand() == WT )
 						src.d_state = 6
 						src.icon_state = "r_wall-6"
-						new /obj/item/stack/rods( src )
+						PoolOrNew(/obj/item/stack/rods, src)
 						user << "<span class='notice'>The support rods drop out as you cut them loose from the frame.</span>"
 				else
 					user << "<span class='notice'>You need more welding fuel to complete this task.</span>"
@@ -223,7 +223,7 @@
 				if( d_state == 5 && user.loc == T && user.get_active_hand() == W )
 					src.d_state = 6
 					src.icon_state = "r_wall-6"
-					new /obj/item/stack/rods( src )
+					PoolOrNew(/obj/item/stack/rods, src)
 					user << "<span class='notice'>The support rods drop out as you cut them loose from the frame.</span>"
 				return