[facet] use facet name as input name for text widget (eg has_text) we need to ba able to distinguish between text-inputs so we can write a widget for a single facet that uses more than one text input. This fix consists in the diff in cubicweb.facts.js; modifications in facet.py result from this former.

# -*- 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"""