Add a ``schema`` command to cmd ctrl to generate schema image.
This changeset add the new commande and do some refactoring in cwconfig and
schema.py to allow the use of CubicWebNoAppConfiguration with
CubicWebSchemaLoader.
"""map standard cubicweb schema to xml vocabularies
:organization: Logilab
:copyright: 2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""
from yams import xy
xy.register_prefix('http://purl.org/dc/elements/1.1/', 'dc')
xy.register_prefix('http://xmlns.com/foaf/0.1/', 'foaf')
xy.register_prefix('http://usefulinc.com/ns/doap#', 'doap')
xy.add_equivalence('creation_date', 'dc:date')
xy.add_equivalence('created_by', 'dc:creator')
xy.add_equivalence('description', 'dc:description')
xy.add_equivalence('CWUser', 'foaf:Person')
xy.add_equivalence('CWUser login', 'dc:title')
xy.add_equivalence('CWUser surname', 'foaf:Person foaf:name')