Removed Request and Response Traits

This Pull Request removes the Request and Response traits in favor of keeping them
as simple renames of the Request and ResponseWriter objects provided by rust-http.

This refactor provides a significant benefit in terms of code length and understandability,
allowing Ingot and Furnace to no longer take type parameters and shortening Iron's type
parameters to include only Furnace.

This makes code working with and implementing Ingots significantly shorter and easier to
work with, and has almost no downsides as the Request and Response traits where
method-for-field re-implementations of Request and ResponseWriter.