web/application: instantiate the repository outside of CubicWebPublisher This improves decoupling and allows ``CubicWebPublisher`` user to choose which argument are used during ``Repository`` instantiation. In particular is allows caller to provide a ``TaskManager``. The `vreg` argument of publisher is made mandatory. See CubicWebPublisher docstring for details. Related to #2249513

# -*- 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.
"""