[toward py3k] rewrite has_key() (part of #2711624)
The `has_key` method is not in Python3K but dict supports __contains__ check for
ages.
# -*- 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 specific hooks and operations"""