* Add expiry dates and individual conditions to gift cards
* Display refund gift cards with more details and prettier interface
* Allow to set gift card expiry and conditions when cancelling event
* Extend gift card search
* Fix#1565 -- Some gift card filters
* Improve list of gift cards
* Allow to edit gift cards
* Note on validity
* Allow to adjust the cancellation fee without JS
* Introduce cancellation requests
* ignore→delete
* Change a few things after Martin's review
* Add a few tests
* Allow to import orders
* seats, subevents
* Plugin support
* Add docs
* Warn about lack of quota handling
* Control interface test
* Test skeleton
* First tests for the impotr columns
* Add tests for all columns
* Fix question validation
- [x] Provide data model and configuration toggle
- [x] Allow to delete individual test orders
- [x] Add tests
- [x] Add a prominent warning message to the backend if test mode orders exist (even though test mode is off), as this leads to wrong statistics
- [x] Decide if and how to generate invoices for test orders as invoice numbers cannot be repeated or should not have gaps.
- [x] Decide if and how we expose test orders through the API, since our difference pull mechanism relies on the fact that orders cannot be deleted.
- [x] Decide if and how we want to couple test modes of payment providers?
- [ ] pretix.eu: Ignore test orders for billing
- [ ] Adjust payment providers: Mollie, bitpay, cash, fakepayment, sepadebit

- [x] Data model
- [x] display in order view in backend
- [x] review all usages of OrderPositions.objects
- [x] review all usages of order.positions
- [x] review all other model usages
- [x] review plugins
- [x] plugins backwards-compatible API?
- [x] decide on way forward for REST API
- [x] need to cancel fees
- [x] tests
- [ ] plugins
- [ ] gdpr
- [ ] reports
- [x] docs
* Refs #99 -- Fix stripe support for zero-decimal currencies
* Add new money formatting method
* Force decimal places in many places
* Locale-aware currency rendering
* Fix currencies in more places
* More currency fixes