Auto-brewing upgrade

[ramonGonzEdu]

An upgrade that would automatically brew potions with the items in the inventory and the filter so it has (3?) of each in the backpack at all times. This would work really well with the potion drinking upgrade mentioned in #146 . You would either filter it by ingredients (4 pairs of potion base + modifier) or by final product (would have a slot for each potion you want, but implementation would have to lookup recipes and handle multiple recipes)