Refactored order process to support anonymous registration without a code in the URL.
Resolved #280. Essentially what was proposed in #230.
Corrected admin behavior of applying discounts.
Switched to using stringed event pk for order code session storage.
Also implemented clearing of order code from session upon purchase + redirect to canonical order URL.
Revert "Made event root canonical URL that provides meta data and redirects actual users via JS."

This reverts commit 1c4a944ef16d346858029cbe25d12096c17ce088.
Switched og:url for events to be the shop page.
`brambling_event_order_shop` should be `brambling_event_shop`
Corrected clearing of session_orders store on checkout.
Force checking of cart expiration on all order views.
Corrected cart expiration check in OrderMixin to account for not having an order.
Removed incorrect csrf hacks in favor of c039c5e.
Merge pull request #281 from littleweaver/ticket/280

Ticket/280 - handle order codes as session variables