Events for entering verified flow & buying
Added refund datetime info to Orders, OrderItems

Finance would like to have info about the date any given refund is requested.

This commit adds a refund_requested_time field to OrderItem and a refund_time to Order.

When a user *requests* a refund, the refund_requested_time field on OrderItem is updated; when a user actually *receives* their refund, the refund_time on Order is updated.

Note that only the refund_requested_teim field is actually used right now; later on, when we're able to actually automate the process of actually giving users refunds, we will start usings Order's refund_time field.
Disabled video caption tests that failed in master
Disabled another video test that failed in master
Response to CR
Quick fix
Rebase to re-prepare PR
dummy commit
Removed old migration
Fixed acceptance test
Response to CR

Switched upgrade info to use cookies, renamed variables, removed a migration, fixed tests and javascript