Fixed issue with modelformsets not saving because we weren't calling the superclass' form_valid method.

Tidied up a few bits too

Conflicts:
	oscar/apps/basket/urls.py
	oscar/apps/checkout/urls.py
	oscar/apps/checkout/views.py
	oscar/apps/customer/urls.py
	oscar/apps/customer/views.py
	oscar/apps/dynamic_images/__init__.py
	oscar/apps/dynamic_images/response_backends.py
	oscar/apps/product/management/commands/import_images.py
	oscar/apps/product/reviews/urls.py
	oscar/apps/product/urls.py
	oscar/apps/product/utils.py
	oscar/templates/oscar/checkout/checkout.html

tests

Uses a different template and redirect for logged-in users

Uses a class-based reimplementation of Django's existing function-based login view. The view also handles registration at the same URL endpoint. It depends on the submit button having a name of "login" or "registration" to determine which form was POSTed.

Auth is done using email addresses rather than username (which is a randomly generated string). The registration process enforces uniqueness, but this won't be enforced anywhere else, so we need to be careful not to duplicate email addresses in the admin or something.

Categories are hierarchies, modelled using django-treebeard and the "Materialized Path" model. Each product can exist in multiple categories, with one flagged as canonical (not yet constrained to just one).

Categories can be added to a product with item.add_category_from_breadcrumbs(string)

The string should be in the form of a simple breadcrumb trail, eg:

"Books > Fantasy > Epic"

The string gets split on the '>' character and converted into categories (they get created if they don't already exist.

There's also a CategoryView which lets you browse the products via the hierarchy, doesn't yet support search queries or faceting.

Removed some templates that shouldn't really be defined by oscar

Basket app now uses Application object

Users can now add/edit/delete their USER addresses
from the checkout shipping address view.

Conflicts:
	oscar/apps/basket/views.py
	oscar/apps/checkout/views.py
	oscar/apps/customer/views.py
	oscar/apps/product/reviews/views.py
	oscar/apps/product/views.py
	oscar/apps/promotions/urls.py
	oscar/templates/oscar/checkout/gateway.html

Conflicts:
	oscar/apps/customer/views.py

convention