Add support for reserved seating (#1228)

* 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

src/pretix/presale/urls.py

@@ -27,6 +27,10 @@ frame_wrapped_urls = [
         name='event.checkout'),
     url(r'^redeem/?$', pretix.presale.views.cart.RedeemView.as_view(),
         name='event.redeem'),
+    url(r'^seatingframe/$', pretix.presale.views.event.SeatingPlanView.as_view(),
+        name='event.seatingplan'),
+    url(r'^(?P<subevent>[0-9]+)/seatingframe/$', pretix.presale.views.event.SeatingPlanView.as_view(),
+        name='event.seatingplan'),
     url(r'^(?P<subevent>[0-9]+)/$', pretix.presale.views.event.EventIndex.as_view(), name='event.index'),
     url(r'^waitinglist', pretix.presale.views.waiting.WaitingView.as_view(), name='event.waitinglist'),
     url(r'^$', pretix.presale.views.event.EventIndex.as_view(), name='event.index'),