[Web-Request] Use rich header (closes #2204164)
Unify header management. All web request use the Headers class now (imported
from twisted). Code dedicated to header management have been merged into the
base WebRequest class.
# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s precreate script, executed at instance creation time or when
the cube is added to an existing instance, before the schema is serialized.
This is typically to create groups referenced by the cube'schema.
"""