[forms] the last touch: handle inlined relation forms as fields
by introducing a simple InlinedRelationField. This makese things
more flexible while removing a lost of overriding necessary.
"""common to all configuration
:organization: Logilab
:copyright: 2001-2010 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
"""