* Initial work on seating
* Add seat guids
* Add product_list_top
* CartAdd: Ignore item when a seat is passed
* Cart display
* product_list_top → render_seating_plan
* Render seating plan in voucher redemption
* Fix failing tests
* Add tests for extending cart positions with seats
* Add subevent_forms to docs
* Update schema, migrations
* Dealing with expired orders
* steps to order change
* Change order positions
* Allow to add seats
* tests for ocm
* Fix things after rebase
* Seating plans API
* Add more tests for cart behaviour
* Widget support
* Adjust widget tests
* Re-enable CSP
* Update schema
* Api: position.seat
* Add guid to word list
* API: (sub)event.seating_plan
* Vali fixes
* Fix api
* Fix reference in test
* Fix test for real
* Decrement voucher usage counter when deleting testmode orders
* Only decrement voucher usage counter for uncancelled orders and on uncancelled positions
* Have the tests actually test something
* Change semantics of changing orders
This basically does two things to the "Change products" view of orders and the
OrderChangeManager program API:
1) It decouples changing items or subevents from changing prices.
OrderChangeManager.change_item() and .change_subevent() no longer
touch the price of a position. Instead .change_price() needs to be
called explicitly. However, a client-side JavaScript component now
*proposes* a new price based on the changed item or subevent.
2) The user interface now exposes the possibility of doing multiple
things at the same time, i.e. changing the item, subevent and price
in the same operation. OrderChangeManager already allowed this
before.
(1) is basically a consequence of (2), while (2) is a prerequesite for
e.g. the `seating` branch, where changing the subevent will always
require changing the seat.
* Add tests for price calculation API
* Original price for variations
* Documentation
* API-GET
* Fix existing tests to accomodate new attribute
* Test for variation's original_price on API
* Upgrade django and stuff
* Update to Django 2.2 and recent versions of similar packages
* Provide explicit orderings to all models used in paginated queries
* Resolve naive datetime warnings in test suite
* Deal with deprecation warnings
* Fix sqlparse version
