* add drag and drop to categories
* add drag and drop to products
* add light grey background to dragged element
* add missing th, add sr-only desc of columns
* group up/down/move elements
* improve visualizing drag-area by dimming others
* change up/down-links to buttons in form-post
* limit sorting to POST requests
Co-authored-by: Raphael Michel <michel@rami.io>
* TicketOutput-Providers: Make preview optional; download/attachable optional; optional specific target; update doc
* Spelling fixes in doc
* Changes after code-review
* Changes after code-review
* Commit missing template file
* Allow for redirects instead of files
* Return HTTPResponse with Content-Type text/uri-list on API
* Update API-doc
* Add viewable to spellinglist, fixing doc-test
- [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
* First stab at notification settings
* Add "global" setting for notification levels
* Trigger notification task
* Get users with permission for event
* Actually send notification emails
* More notifications
* Allow to turn off notifications
* Link in email to pause all notifications
* Add NotificationType to wordlist
* Add notification tests
* Add documentation
* Rebase fixes
* Ref #552 -- Add icon to expansible panels
Offer informative feedback to user by showing icons to indicate
expansible panels.
* Fix wrongly removed JavaScript line