Django 1.8 supports Python 3.5. It does raise a DeprecationWarning,
which is safe to ignore. We only care about DeprecationWarnings in our
own code.

And it seems that Travis wants all allowed failures listed explicitly,
so we do that. It should now pass again.

As part of my last PR, I had USE_LESS enabled for testing purposes and
accidentally committed the setting. By default, we don't want to run the
(somewhat slow) pre-processor!

Update templates so that the product title isn't automatically escaped.

Fix create_line_reference for options already enconded to utf-8

Django 1.9 support

In Django 1.9 the FormView.form is added via get_context_data(), make
sure we call this in CheckoutSessionMixin.get_context_data()

The debug-toolbar-template-timings-panel isn't compatible with 1.9 yet

 - Set Meta.app_label on models created in the tests
 - Use logging.NullHandler instead of django.utils.log.NullHandler
 - Use oscar.core.loading.get_model() instead of django's get_model
 - Remove template tags '{% load url from future %}'

In Django 1.9 the decorator from six is used so simplify the test to
just check for a __unicode__ method

This is required in Django 1.9, see
https://docs.djangoproject.com/en/1.8/topics/auth/default/#session-invalidation-on-password-change

Remove django-compressor

django-compressor used to trigger processing of the less files during
development. But with the browser-based compiler, an easy replacement is
available. This even lowers the barrier to altering styles, because
getting npm up and running isn't required.

Offline compilation isn't impacted.

Using the most current less version seems to not cause any trouble, so I
removed the version requirement.

django-compressor served it's purpose, but given the advent of
more and more frontend JS work, and the accompanying build tools (grunt,
gulp, etc.), it makes less and less sense to use compressor. Jannis
Leidel himself also stepped back from maintaining it.

In my experience with Oscar project, it has also become a bit of a
liability to have compressor as a dependency. Most projects don't use it
any more, but it's not easy to disable/override because all our
templates include it.

So, let's keep things simple and remove it as a dependency. That paves
the way for using other tools, while it's always easy to add back.

Use class=text-right instead of inline style.

Update templates with .icon-warning to .icon-warning-sign.

use range.all_products instead of range.included_products where necessary

Fix import ordering (implement isort)

This also adds isort settings.

Use jQuery().prop instead of jQuery().attr for toggling checked for d…

Clarify superuser login information

Replace assert statements with appropriate assert* method.

Remove all instances of the number 1 being hard-coded in translation strings.

Fix email template extending the wrong base template

This patch makes the number being pluralised available and used in every translation string where 1 was previously hard-coded. Individual translators can still provide translations that don't use the variables, if they so wish.

Replace 'assert' with 'assert*' method.

Convert tests.unit.forms.widget_tests to use TestCase class.

Convert bankcard tests to use TestCase.

Convert tests.unit.logging_tests to use TestCase.

Fix missing page_url promotions form field

If no shipping method was selected the shipping_charge was a Decimal
instead of a Price instance.

The plain text template was extending the HTML base instead of the text one.