Used get_username() instead of referencing the username attribute directly
Drop unused OSCAR_BASKET_COOKIE_SAVED setting

It must be left over from more glorious times.
get_cookie_key method for BasketMiddleware for multi-sites

In a multi-site scenario, one might want different cookie baskets
per site. In that case, an easy way to achieve this is to set different
cookie keys per site. The introduced method provides an easy hook to do
just that.
Add docstring for product validation

I created this table to get my head around the product validation, and
figured it's probably useful for others.
Merge pull request #1418 from oscaro/fix/username

Used get_username() instead of referencing the username attribute
Simplify shipping template tags

This commit simplifies yet another set of template tags by using
Django's helpers.

Closes #1419.