Add South to manage db schema change
Merge pull request #2 from aquaopaque/tech-db-migration

New Model South for DB migration
Add south into INSTALLED_APPS.
Remove comment from the order, since we want to use south for the order comment part.
Add migration for add filed order comment.
Update README to include db migration commands.
Merge pull request #3 from gregwym/south

Fix South migration issues.
Add paypalrestsdk as dependency.
Refactor init to setup paypal with paypalrestsdk.
Split cart and checkout into two step process.
Fix coupon code checker.
Add collection_extra template tags.
Move checkout form to forms.py.
Add checkout page template and complete create_invoice process.
Round item_cost and item_tax to 2 decimal place.
Add create_payment_for_invoice to create Paypal payment object.
Add Pay on Delivery as new payment status.
Rename to create_raw_payment_for_invoice.
Add Payment model to record each payment.
Create payment object once the paypal raw payment created.