Merge branch 'product-class-use-slug-in-URL' into machtfit

* branch product-class-use-slug-in-URL:
  Use slug instead of id for product_class in URL

https://github.com/tangentlabs/django-oscar/pull/1123
discussion pending

merge arbitrary-number-of-permissions
https://github.com/tangentlabs/django-oscar/pull/1140
merged in 0.7
Merge branch 'django-tables2' into machtfit

* branch django-tables2:
  Move the dashboard product list to django-tables2
Add missing dependency
Keep current tab and ordering when returning to the list after editing