--------

- In support of making it easier to configure applications which are
  "secure by default", a default permission feature was added.  If
  supplied, the default permission is used as the permission string to
  all view registrations which don't otherwise name a permission.
  These APIs are in support of that:

  - A new constructor argument was added to the Configurator:
    ``default_permission``.

  - A new method was added to the Configurator:
    ``set_default_permission``.

  - A new ZCML directive was added: ``default_permission``.

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

- Added documentation for the ``default_permission`` ZCML directive.

- Added documentation for the ``default_permission`` constructor value
  and the ``set_default_permission`` method in the Configurator API
  documentation.

- Added a new section to the "security" chapter named "Setting a
  Default Permission".

- Document ``renderer_globals_factory`` and ``request_factory``
  arguments to Configurator constructor.

No foreigners were harmed in the coding of this feature.

  This section contains detailed ZCML directive information, some of
  which was removed from various narrative chapters.

  functionality is replaced internally).

  following addtional attributes: ``attr``, ``renderer``, and
  ``wrapper``.  These have the same meaning as they do in the context
  of a ZCML ``view`` directive.

  instead rely on queryAdapter and a manual default to
  ModelGraphTraverser.

- Speed: do not register an IContextURL in configure.zcml; instead
  rely on queryAdapter and a manual default to TraversalContextURL.

- General speed microimprovements for helloworld benchmark: replace
  try/excepts with statements which use 'in' keyword.

  return value of any view callble into a string.  It is documented in
  the "Views" narrative chapter.