Allow for vouchers that are valid for multiple items

src/pretix/base/migrations/0020_auto_20160418_2106.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.2 on 2016-04-18 21:06
+from __future__ import unicode_literals
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0019_auto_20160326_1139'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='voucher',
+            name='quota',
+            field=models.ForeignKey(blank=True, help_text='If enabled, the voucher is valid for any product affected by this quota.', null=True, on_delete=django.db.models.deletion.CASCADE, related_name='quota', to='pretixbase.Quota', verbose_name='Quota'),
+        ),
+        migrations.AlterField(
+            model_name='questionanswer',
+            name='options',
+            field=models.ManyToManyField(blank=True, related_name='answers', to='pretixbase.QuestionOption'),
+        ),
+    ]

src/pretix/base/migrations/0021_auto_20160418_2117.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.2 on 2016-04-18 21:17
+from __future__ import unicode_literals
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0020_auto_20160418_2106'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='voucher',
+            name='item',
+            field=models.ForeignKey(blank=True, help_text="This product is added to the user's cart if the voucher is redeemed.", null=True, on_delete=django.db.models.deletion.CASCADE, related_name='vouchers', to='pretixbase.Item', verbose_name='Product'),
+        ),
+    ]

src/pretix/base/migrations/0022_merge.py

@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.2 on 2016-04-23 09:44
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0020_auto_20160421_1943'),
+        ('pretixbase', '0021_auto_20160418_2117'),
+    ]
+
+    operations = [
+    ]