Features
--------

- The ``Configurator`` object now has two new methods: ``begin`` and
  ``end``.  The ``begin`` method is meant to be called before any
  "configuration" begins (e.g. before ``add_view``, et. al are
  called).  The ``end`` method is meant to be called after all
  "configuration" is complete.

  Previously, before there was imperative configuration at all (1.1
  and prior), configuration begin and end was invariably implied by
  the process of loading a ZCML file.  When a ZCML load happened, the
  threadlocal data structure containing the request and registry was
  modified before the load, and torn down after the load, making sure
  that all framework code that needed ``get_current_registry`` for the
  duration of the ZCML load was satisfied.

  Some API methods called during imperative configuration, (such as
  ``Configurator.add_view`` when a renderer is involved) end up for
  historical reasons calling ``get_current_registry``.  However, in
  1.2a5 and below, the Configurator supplied no functionality that
  allowed people to make sure that ``get_current_registry`` returned
  the registry implied by the configurator being used.  ``begin`` now
  serves this purpose.  Inversely, ``end`` pops the thread local
  stack, undoing the actions of ``begin``.

  We make this boundary explicit to reduce the potential for confusion
  when the configurator is used in different circumstances (e.g. in
  unit tests and app code vs. just in initial app setup).

  Existing code written for 1.2a1-1.2a5 which does not call ``begin``
  or ``end`` continues to work in the same manner it did before.  It
  is however suggested that this code be changed to call ``begin`` and
  ``end`` to reduce the potential for confusion in the future.

- All ``paster`` templates which generate an application skeleton now
  make use of the new ``begin`` and ``end`` methods of the
  Configurator they use in their respective copies of ``run.py`` and
  ``tests.py``.

Documentation
-------------

- All documentation that makes use of a ``Configurator`` object to do
  application setup and test setup now makes use of the new ``begin``
  and ``end`` methods of the configurator.

Bug Fixes
---------

- When a ``repoze.bfg.exceptions.NotFound`` or
  ``repoze.bfg.exceptions.Forbidden`` *class* (as opposed to instance)
  was raised as an exception within a root factory (or route root
  factory), the exception would not be caught properly by the
  ``repoze.bfg.`` Router and it would propagate to up the call stack,
  as opposed to rendering the not found view or the forbidden view as
  would have been expected.