Allow quotas to "close" when once full (#1344)

* Model

* Some UI

* API and logging

* Permission check

* Add tests

* Move option around

src/pretix/base/migrations/0128_auto_20190715_1510.py

@@ -0,0 +1,26 @@
+# Generated by Django 2.2.1 on 2019-07-15 15:10
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+import pretix.base.models.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0127_auto_20190711_0705'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='quota',
+            name='close_when_sold_out',
+            field=models.BooleanField(default=False),
+        ),
+        migrations.AddField(
+            model_name='quota',
+            name='closed',
+            field=models.BooleanField(default=False),
+        ),
+    ]