stop using meta attribute from yams schema. Use instead sets defining meta relations and another defining schema types. Refactor various schema view based on this
""" CW - nevow/twisted client
:organization: Logilab
:copyright: 2001-2009 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
"""