[session/transaction] move entity cache management on session
A new utility method is added for that. It is similar to the one used for
attribute access. code is copy pasted as his. Function documentation is added.
# -*- 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"""