* standardize use of check-in
* split on occurrence of "checkin_*"
Instead of skipping when encountering "checkin_*", we now split and only
pass the second part to the spell-checker. This fixes the aforementioned
problem.
* fix spelling issue with checkins
* Data model and migration
* Some backwards compatibility
* CRUD for checkin lists
* Show and perform checkins
* Correct numbers in table and dashboard widget
* event creation and cloning
* Allow to link specific exports and pass options per query
* Play with the CSV export
* PDF export
* Collapse exports by default
* Improve PDF exporter
* Addon stuff
* Subevent stuff, pretixdroid tests
* pretixdroid tests
* Add CRUD API
* Test compatibility
* Fix test
* DB-independent sorting behavior
* Add CRUD and coyp tests
* Re-enable pretixdroid plugin
* pretixdroid config
* Tests & fixes
