Migrating from NuxMetaDirectory
===============================

Context
-------

NuxMetaDirectories has been deprecated in CPS3 in favor of CPSDirectories
(cleaner architecture, based on CPSSchemas).

Changes
-------

1. Change all references to 'portal_metadirectories' to
   'portal_directories'.

2. Replace 'display_prop' (property of a directory) with 'title_field'.

3. Replace references to directory_* skins by cpsdirectory_*. Beware
   that some skin names have changed, and that the parameters to
   cpsdirectory_entry_view are now 'dirname' and 'id' (not 'entry_id').

4. Calls to getEntry('foo') will not return None anymore if the entry
   does not exist but raise KeyError. If you want None returned, use
   getEntry('foo', default=None).

5. Replace getSearchableSchemaKeys by querying the schema directly for
   the fields that you want.

6. Be aware that results from a searchEntry is different than before.

   If there are no return_fields, you get::

     ['id1', 'id2', etc.]

   If there is a return_fields parameter, you get::

     [('id1', {'field1': value1, 'field2': value2}),
       ('id2', {'field1': value3, 'field2': value4}),
       etc.
     ]

   return_fields being in this example ('field1', 'field2')
