Merge pull request #234 from atheiste/master

Cart views sanitize inputs
Make sure the checkout confirmation redirect is not a permanent one.

Permanent redirects may be cached by the browser or a reverse proxy, causing
the view to be ignored. The order status then won't get updated.
Merge pull request #237 from sephii/checkout-redirect

Make sure the checkout confirmation redirect is not a permanent one
Merge branch 'master' of https://github.com/divio/django-shop