woothemes/woocommerce — pull request #2556 by maxrice (2013-03-01 19:24:48+00:00)
Title: Allow orders with custom statuses to use the pay page

Adds a `woocommerce_valid_order_statuses_for_payment` filter so plugins
that orders with custom statuses can be paid on the pay page. This is needed for the pre-orders extension so that orders with the `pre-ordered` status can be paid later when the pre-order is available.