Changes 3.8.0:
* New module ``zope.interface.registry``.  This is code moved from
  ``zope.component.registry`` which implements a basic nonperistent component
  registry as ``zope.interface.registry.Components``.  This class was moved
  from ``zope.component`` to make porting systems (such as Pyramid) that rely
  only on a basic component registry to Python 3 possible without needing to
  port the entirety of the ``zope.component`` package.  Backwards
  compatibility import shims have been left behind in ``zope.component``, so
  this change will not break any existing code.
* New ``tests_require`` dependency: ``zope.event`` to test events sent by
  Components implementation.  The ``zope.interface`` package does not have a
  hard dependency on ``zope.event``, but if ``zope.event`` is importable, it
  will send component registration events when methods of an instance of
  ``zope.interface.registry.Components`` are called.
* New interfaces added to support ``zope.interface.registry.Components``
  addition: ``ComponentLookupError``, ``Invalid``, ``IObjectEvent``,
  ``ObjectEvent``, ``IComponentLookup``, ``IRegistration``,
  ``IUtilityRegistration``, ``IAdapterRegistration``,
  ``ISubscriptionAdapterRegistration``, ``IHandlerRegistration``,
  ``IRegistrationEvent``, ``RegistrationEvent``, ``IRegistered``,
  ``Registered``, ``IUnregistered``, ``Unregistered``,
  ``IComponentRegistry``, and ``IComponents``.
* No longer Python 2.4 compatible (tested under 2.5, 2.6, 2.7, and 3.2).

(adam)