Updates storage costs

Storage cost of an item is now twice that of the next smallest item, instead of being equal to the w_class.
Items with w_class 1 or 2 are unaffected. This produces much better behaviour for containers that are limited
by storage space instead of slots, such as how toolboxes are planned to work in a future update.

code/modules/reagents/reagent_containers/glass.dm

@@ -12,6 +12,7 @@
 	amount_per_transfer_from_this = 10
 	possible_transfer_amounts = list(5,10,15,25,30,60)
 	volume = 60
+	w_class = 2
 	flags = OPENCONTAINER
 
 	var/label_text = ""