- Restructure into unit and integration tests.
- Add more tests for the various basket properties.

This change handles the backwards compatiblity issue of adding a
required stockrecord field onto the basket line model.

When a basket in encountered which has a line without a stockrecord, we
delete it and attempt to re-add it to the basket.

We also merge the middleware together for simplicity.

This is to support US-like sites where sales taxes are only known once
the customer enters their shipping address.

This requires several changes to templates to show prices exclusive of
tax when tax isn't known.

Offers are currently now applied until taxes are known as it is unclear
to me whether to use the tax-exclusive prices to determine whether
customer's meet value conditions.  This may change later.

Hmmm, this turned out to be a monster commit.  This change allows the
basket to be able to correctly calculate prices including tax.

It also requires a whole load of test changes since all baskets now
require a strategy instance to be assigned.

Rather than a StockRecord instance.  This makes it much simpler.

This are to replace the partner wrappers.

Useful in templates where the bankcard form is rendered.  Eg:

    {{ bankcard_form.bankcard.obfuscated_number }}

Plus reorganise tests

Validation is based on wikipedia list of postal codes [1]. Formats were
converted into regexes for countries.

1: http://en.wikipedia.org/wiki/List_of_postal_codes

Fixes #753

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