Replaces [stack]/fifty atoms with atoms that spawn the normal stack

The stack/fifty objects were really buggy, this should fix all of that in one go.

code/datums/supplypacks/materials.dm

@@ -9,34 +9,34 @@
 
 /datum/supply_packs/materials/metal50
 	name = "50 metal sheets"
-	contains = list(/obj/item/stack/material/steel/fifty)
+	contains = list(/obj/fiftyspawner/steel)
 	cost = 10
 	containertype = /obj/structure/closet/crate
 	containername = "Metal sheets crate"
 
 /datum/supply_packs/materials/glass50
 	name = "50 glass sheets"
-	contains = list(/obj/item/stack/material/glass/fifty)
+	contains = list(/obj/fiftyspawner/glass)
 	cost = 10
 	containertype = /obj/structure/closet/crate
 	containername = "Glass sheets crate"
 
 /datum/supply_packs/materials/wood50
 	name = "50 wooden planks"
-	contains = list(/obj/item/stack/material/wood/fifty)
+	contains = list(/obj/fiftyspawner/wood)
 	cost = 10
 	containertype = /obj/structure/closet/crate
 	containername = "Wooden planks crate"
 
 /datum/supply_packs/materials/plastic50
 	name = "50 plastic sheets"
-	contains = list(/obj/item/stack/material/plastic/fifty)
+	contains = list(/obj/fiftyspawner/plastic)
 	cost = 10
 	containertype = /obj/structure/closet/crate
 	containername = "Plastic sheets crate"
 
 /datum/supply_packs/materials/cardboard_sheets
-	contains = list(/obj/item/stack/material/cardboard/fifty)
+	contains = list(/obj/fiftyspawner/cardboard)
 	name = "50 cardboard sheets"
 	cost = 10
 	containertype = /obj/structure/closet/crate
@@ -48,8 +48,8 @@
 	containername = "Imported carpet crate"
 	cost = 15
 	contains = list(
-					/obj/item/stack/tile/carpet/fifty,
-					/obj/item/stack/tile/carpet/blue/fifty
+					/obj/fiftyspawner/carpet,
+					/obj/fiftyspawner/bluecarpet
 					)
 
 
@@ -58,4 +58,4 @@
 	containertype = /obj/structure/closet/crate
 	containername = "Linoleum crate"
 	cost = 15
-	contains = list(/obj/item/stack/tile/linoleum/fifty)
+	contains = list(/obj/fiftyspawner/linoleum)

code/datums/supplypacks/supply.dm

@@ -53,7 +53,7 @@
 /datum/supply_packs/supply/shipping
 	name = "Shipping supplies"
 	contains = list(
-				/obj/item/stack/material/cardboard/fifty,
+				/obj/fiftyspawner/cardboard,
 				/obj/item/weapon/packageWrap = 4,
 				/obj/item/weapon/wrapping_paper = 2,
 				/obj/item/device/destTagger,