Features
--------

- Add ``pyramid.config.Configurator.add_resource_url_adapter`` API method.
  See the Hooks narrative documentation section entitled "Changing How
  pyramid.request.Request.resource_url Generates a URL" for more information.
  This is not a new feature, it just provides an API for adding a resource
  url adapter without needing to use the ZCA API.

- A new interface was added: ``pyramid.interfaces.IResourceURL``.  An adapter
  implementing its interface can be used to override resource URL generation
  when ``request.resource_url`` is called.  This interface replaces the
  now-deprecated ``pyramid.interfaces.IContextURL`` interface.

- The dictionary passed to a resource's ``__resource_url__`` method (see
  "Overriding Resource URL Generation" in the "Resources" chapter) now
  contains an ``app_url`` key, representing the application URL generated
  during ``request.resource_url``.  It represents a potentially customized
  URL prefix, containing potentially custom scheme, host and port information
  passed by the user to ``request.resource_url``.  It should be used instead
  of ``request.application_url`` where necessary.

- The ``request.resource_url`` API now accepts these arguments: ``app_url``,
  ``scheme``, ``host``, and ``port``.  The app_url argument can be used to
  replace the URL prefix wholesale during url generation.  The ``scheme``,
  ``host``, and ``port`` arguments can be used to replace the respective
  default values of ``request.application_url`` partially.

- A new API named ``request.resource_path`` now exists.  It works like
  ``request.resource_url`` but produces a relative URL rather than an
  absolute one.

- The ``request.route_url`` API now accepts these arguments: ``_app_url``,
  ``_scheme``, ``_host``, and ``_port``.  The ``_app_url`` argument can be
  used to replace the URL prefix wholesale during url generation.  The
  ``_scheme``, ``_host``, and ``_port`` arguments can be used to replace the
  respective default values of ``request.application_url`` partially.

Backwards Incompatibilities
---------------------------

- The ``pyramid.interfaces.IContextURL`` interface has been deprecated.
  People have been instructed to use this to register a resource url adapter
  in the "Hooks" chapter to use to influence ``request.resource_url`` URL
  generation for resources found via custom traversers since Pyramid 1.0.

  The interface still exists and registering such an adapter still works, but
  this interface will be removed from the software after a few major Pyramid
  releases.  You should replace it with an equivalent
  ``pyramid.interfaces.IResourceURL`` adapter, registered using the new
  ``pyramid.config.Configurator.add_resource_url_adapter`` API.  A
  deprecation warning is now emitted when a
  ``pyramid.interfaces.IContextURL`` adapter is found when
  ``request.resource_url`` is called.

Misc
----

- Change ``set_traverser`` API name to ``add_traverser``.

Ref #438.