Add a port of django-crispy-forms specifically for Django 2.1
This uses the approach taken by kai@ for various django ports
in r492690: Depend on Django 2.1, require python 3.5 or
higher and add a conflict variable to the Django 1.x version
of the port.
Minor fix to pkg-descr and Makefile to pacify portlint while
I was there.
PR: 236681