This change adds a uniqueness constraint on user addresses to prevent
duplicates.  A few changes follow:

- The user address forms in account and checkout are modified to take a
  user as a constructor arg so uniqueness can be checked.

- The assignment of a user when creating a new address has been moved
  into the form.

Also I moved the generate_hash fn up to the Address superclass as it's
possible that it might be used in other Address classes.

The backported version didn't explicitly create the ProductAttribute
instances before assigning and so they didn't save.

Fields now more self-contained, the bankcard form is much simpler.

This makes creating simple shipping repositories simpler as you only
need to override the methods attribute.

This allows updating code in both places, if necessary. Getting Django
1.5 support would be painful otherwise. This also removes the circular
dependency of django-oscar-testsupport on Oscar.

The requirements were merged. The imports were updated
accordingly. Unused imports in the touched files were removed. No
further changes.

* Tidy implementation of validator
* Tests improved and moved to tests/integration (as they call resolve
  internally)

When adding to the basket, products with options were treated as
different products for each combination of options. This allowed adding
more products into the basket than are available for purchase.

The handling has been updated to sum up the already added quantity of
the product regardless of options.

Fixes #665

This is required for multiprocess testing to work (eg ./runtests.py
--processes=2)

Fixes #614

As they save stuff...

We now check in the OrderCreator for this attribute and only allocate if
it is true.

Fixes #671

The clean method was raising a KeyError when the date fields were empty.

They aren't treated specially any more.  They become part of the
'applications' collection rather than being attached to the basket.

This paves the way for custom benefits to return successful applications
that don't lead to a discount.

By adding the __setstate__ method an infinite loop is avoided regarding
the use of __getattr__ on the ProductAttributesContainer model.

Moving tests into appropriate folder

So stopwords can be moved from slugs

...as they are all integration tests (they save stuff).

They use the DB so they are not really unit tests.

shipping/models:ShippingMethod was missing the is_discounted attribute that
exists in the de-facto superclass in shipping/base:ShippingMethod.

Also added a few comments to clarify how they relate to each other, and
tests to check if is_discounted is present on various instances of
ShippingMethods.

* This gives more flexibility to offers in how they are used.
* Am using a jQuery datetimepicker from: http://trentrichardson.com/examples/timepicker/

My bad.  Committed this test through careless use of 'git add .' as part
of commit 80c1b0b1a7.

I forgot to modify the test config to account for django-compressor.

Following guidance from Tangent's UX team (blame them!)

* Split 'metadata' step into 'name and description' and 'restrictions'
* Add progress bar
* Add summary of entered data in right-hand sidebar
* Clean up breadcrumbs and URLs

Still needs from FED love.

Uses new status on offer model.

Distinguish it from the other folders which each define a category of
test.

Use global instead of per-method test dates.

This makes it more efficient to load offers now that we can't simply use
the date filters to exlucde unavailable offers.

The is_active field has been reworked to depend on the
get_max_applications method.

The save method of ConditionalOffer now auto-sets status.

Fixes #403