* Removing the dependency on AD::Request and AD::Response
* Moving the logic for the request and response object
into a new module that is included by default.
* Changing Renderer and Redirector to use self.headers,
self.content_type, and self.status, which have very basic
default implementations on AC::Http. When RackConvenience
is included (which it is by default on AC::Base), the full
Request/Response logic is used instead of the simple logic.