(feat) Updated the Furnace Trait.
(feat) Setup IronFurnace as Clone + Send
(feat) Added skeleton of forge for IronFurnace
(feat) Completed IronFurance forge implementation.
(fix) Iterate through the exit stack in reverse.
(refactor) Moved impl of Clone for Ingots to ingot module.
(cleanup) Removed confusing variable name.
Merge pull request #4 from reem/feat/ironfurnace

(feat) Implemented IronFurnace