This makes some changes to our configuration, templates, template tags,

and imports to be compatible with Django 1.6 and higher. Some of the

imports and code we were using was already deprecated in Django 1.6, but

worked anyway.
Template tags using @simple_tag no longer return content the same way.

They're set to conditionally escape, which impacts some of our tags. A

couple now explicitly use mark_safe(), and another (which is used to

build query strings) that used to not escape now escapes (since the

ampersands should technically be escaped for URLs in HTML).
Template configuration has changed. All new template-related

configuration lives in a TEMPLATES setting, which encompasses the

directories, context processors, and loaders. Our test suite's settings

now retains compatibility with the old style and the new style by

setting the old variables and using it to build the new one.

Unit tests pass on Django 1.6, 1.7, 1.8, 1.9, and 1.10.
Verified that the template and template tag changes producted the

correct output in real use.