Fixes messed up belt_mirror sprites, bag missing sprite and merchant mecha weapons (#3712)

-fixes #3707
-fixes #3711
-fixes the science courier bag having no sprite
-fixes a lot of items being brown by accident

code/datums/trading/vox.dm

@@ -49,7 +49,8 @@
 	possible_trading_items = list(
 		/obj/item/weapon/gun/projectile/dartgun/vox                          = TRADER_SUBTYPES_ONLY,
 		/obj/item/mecha_parts/mecha_equipment/tool                           = TRADER_SUBTYPES_ONLY,
-		/obj/item/mecha_parts/mecha_equipment/weapon/ballistic               = TRADER_SUBTYPES_ONLY,
+		/obj/item/mecha_parts/mecha_equipment/weapon                         = TRADER_SUBTYPES_ONLY,
+		/obj/item/mecha_parts/mecha_equipment/weapon/ballistic               = TRADER_BLACKLIST,
 		/obj/item/mecha_parts/mecha_equipment/weapon/ballistic/missile_rack  = TRADER_BLACKLIST,
 		/obj/item/trash                                                      = TRADER_SUBTYPES_ONLY,
 		/obj/item/clothing/accessory                                         = TRADER_ALL,

code/game/objects/items/weapons/storage/backpack.dm

@@ -444,7 +444,7 @@
 /obj/item/weapon/storage/backpack/messenger/tox
 	name = "research messenger bag"
 	desc = "A backpack worn over one shoulder.  Useful for holding science materials."
-	icon_state = "courierbagnt"
+	icon_state = "courierbagtox"
 
 /obj/item/weapon/storage/backpack/messenger/gen
 	name = "geneticist messenger bag"