Install coffin+jinja

* Add coffin+jinja to pip requirements
* Add coffin to INSTALLED_APPS
* Add ninja safestring monkeypatch
Convert app templates to jinja

* Convert HTML templates to jinja
* Update views to use coffin ninja rendering
* Convert all views to individual page view classes
* Update blog post render template tag for ninja
* Add putz dependency (unversioned, always pull in latest)
* Convert post datetimes to project time-zone in blog backend
Switch from coffin to django-jinja

* Actually that worked pretty well
* Got to delete some code and the compat global functions are more explicit
Switch templates to jinja2

* Convert Django templates to jinja2 templates
* Use django_jinja and exclude debug toolbar
* Remove unused django apps and settings
* Create individual class views for all pages
* Add putz dependency (unversioned, always pull in latest)
* Convert post datetimes to project time-zone in blog backend