Refs #39 -- New concept of "teams" (#478)

* New models

* CRUD UI

* UI for adding/removing team members

* Log display for teams

* Fix invitations, move frontend

* Drop old models (incomplete)

* Drop more old stuff

* Drop even more old stuff

* Fix tests

* Fix permission test

* flake8 fix

* Add tests fore the new code

* Rebase migrations

src/pretix/control/views/dashboards.py

@@ -13,7 +13,7 @@ from django.utils.formats import date_format
 from django.utils.translation import ugettext_lazy as _
 
 from pretix.base.models import (
-    Event, Item, Order, OrderPosition, Voucher, WaitingListEntry,
+    Item, Order, OrderPosition, Voucher, WaitingListEntry,
 )
 from pretix.control.signals import (
     event_dashboard_widgets, user_dashboard_widgets,
@@ -207,11 +207,12 @@ def event_index(request, organizer, event):
     for r, result in event_dashboard_widgets.send(sender=request.event):
         widgets.extend(result)
 
+    can_change_orders = request.user.has_event_permisson(request.organizer, request.event, 'can_change_orders')
     qs = request.event.logentry_set.all().select_related('user', 'content_type').order_by('-datetime')
     qs = qs.exclude(action_type__in=OVERVIEW_BLACKLIST)
-    if not request.eventperm.can_view_orders:
+    if not request.user.has_event_permisson(request.organizer, request.event, 'can_view_orders'):
         qs = qs.exclude(content_type=ContentType.objects.get_for_model(Order))
-    if not request.eventperm.can_view_vouchers:
+    if not request.user.has_event_permisson(request.organizer, request.event, 'can_view_vouchers'):
         qs = qs.exclude(content_type=ContentType.objects.get_for_model(Voucher))
 
     a_qs = request.event.requiredaction_set.filter(done=False)
@@ -221,7 +222,7 @@ def event_index(request, organizer, event):
     ctx = {
         'widgets': rearrange(widgets),
         'logs': qs[:5],
-        'actions': a_qs[:5] if request.eventperm.can_change_orders else [],
+        'actions': a_qs[:5] if can_change_orders else [],
         'has_domain': has_domain
     }
 
@@ -242,7 +243,8 @@ def event_index(request, organizer, event):
 def user_event_widgets(**kwargs):
     user = kwargs.pop('user')
     widgets = []
-    events = Event.objects.filter(permitted__id__exact=user.pk).select_related("organizer").order_by('-date_from')
+
+    events = user.get_events_with_any_permission().select_related('organizer')
     for event in events:
         widgets.append({
             'content': '<div class="event">{event}<span class="from">{df}</span><span class="to">{dt}</span></div>'.format(