pkg: drop python 2.5 compatibility (closes #2711624)
2.5 is not common anymore. Dropping compatibility will help moving to a code
base compatible with Python 3.3
# -*- 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 entity's classes"""