(cleanup) Removed Request and Response traits.
(feat) Added Request and Response types.
(cleanup) Removed IronRequest and IronResponse.
(refactor) Refactored Furnace with Request and Response types.
(refactor) Refactored trait dependent IronFurnace to typed StackFurnace.
(refactor) Refactored Ingot with Request and Response types.
(refactor) Refactored Iron to use Request and Response types.
(cleanup) Refactored example to work with new API.
Merge pull request #46 from reem/refactor/remove-request-response

(refactor) Removed Request and Response Traits.