First pull request

Attempt at implementing ordering logic. One thing I did very early was change the WSGI setiings in settings.py from WSGI_APPLICATION = 'apps.wsgi.application' to WSGI_APPLICATION = 'wsgi.application'. Maybe you will have to change back to get this working on your system. I have not accounted for 'quantity' in orderitems. I treat an OrderItem of quantity > 1 as 1 single item order.