dav_auth: admin: add group members as inline to group admin

dav_auth/admin.py

@@ -1,5 +1,21 @@
 from django.contrib import admin
+from django.contrib.auth.admin import GroupAdmin as _GroupAdmin
+from django.contrib.auth.models import Group
 from django.contrib.auth.models import Permission
+from django.utils.translation import ugettext as _
+admin.site.unregister(Group)
+
+
+class UserInLine(admin.TabularInline):
+    model = Group.user_set.through
+    verbose_name = _('Gruppenmitglied')
+    verbose_name_plural = _('Gruppenmitglieder')
+    extra = 0
+
+
+@admin.register(Group)
+class GroupAdmin(_GroupAdmin):
+    inlines = [UserInLine]
 
 
 @admin.register(Permission)