Refs #314 -- Read-only REST API (#513)

* initial commit

* API auth

* Hierarchical URLs

* Add session auth

* Strong hierarchy

* Add filters

* Add i18n fields, questions

* More viewsets and serializers

* Ticket download

* Add OrderPosition serializer

* View-level permissions

* More tests

* More tests

* Add basic API docs

* Add REST API to docs frontpage

* Tests for order endpoints

* Add invoice tests

* Voucher and waitinglist tests

* Doc draft

* order docs

* Docs on all viewsets

* Disable DRF docs, style sphinx, style browsable API

* Fix tests

* deprecated imports

* Test foo

* Attendee names

* Fix migration problems

* Remove browsable API, plugin integration

* Doc fixes

src/pretix/api/views/organizer.py

@@ -0,0 +1,20 @@
+from rest_framework import viewsets
+
+from pretix.api.serializers.organizer import OrganizerSerializer
+from pretix.base.models import Organizer
+
+
+class OrganizerViewSet(viewsets.ReadOnlyModelViewSet):
+    serializer_class = OrganizerSerializer
+    queryset = Organizer.objects.none()
+    lookup_field = 'slug'
+    lookup_url_kwarg = 'organizer'
+
+    def get_queryset(self):
+        if self.request.user.is_authenticated():
+            if self.request.user.is_superuser:
+                return Organizer.objects.all()
+            else:
+                return Organizer.objects.filter(pk__in=self.request.user.teams.values_list('organizer', flat=True))
+        else:
+            return Organizer.objects.filter(pk=self.request.auth.team.organizer_id)