[schema] use json to serialize constraints Require yams 0.43: constraints are serialized to json, which means we need to recreate the actual checks in the database on upgrade. Temporary deps in tox.ini to pull respective changes in yams.

# -*- 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 views/forms/actions/components for web ui"""