unordered_list template filter does not work with lazy translations

[Jonas Haag]

I would expect that the following assertion holds true:

{{
from django.utils.translation import ugettext_lazy as _
from django.template.defaultfilters import unordered_list

assert unordered_list([, _('lazy')]) == unordered_list([, 'lazy']))
}}

I.e., unordered_list handles lazy translations as if they were strings.

This used to work in Django < 1.8, more specifically before the patch to this ticket: https://code.djangoproject.com/ticket/23260

This bug exists in all versions 1.8–master.

Pull request follows.