Added controller-level etag additions that will be part of the action etag computation *Jeremy Kemper/DHH*

Removed max-stale from the setting the cache-headers in the response as max-stale is a cache request header.

Revert "Added ActiveRecord::Base#last_modified to work with the new fresh_when/stale? conditional get methods from Action Pack"

Needless indirection with no added value.

This reverts commit 535853e8.

Added ActiveRecord::Base#last_modified to work with the new fresh_when/stale? conditional get methods from Action Pack

	Time#utc does not need to be called when passing the object to :last_modified 	since it is called internally to Rails.

  * Significantly simplifies setting and modifying cache control in other areas

Break up DependencyModule's dual function of providing a "depend_on" DSL and "included" block DSL into separate modules. But, unify both approaches under AS::Concern.

This reverts commit 0cac68d3.

  * 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.