implement model changes

- add new domains.apps.AppConfig to allow translatable app description for
  domains app
- link domains to a customer
- extract common functionality from domains.models.MailDomain into abstract
  domains.models.DomainBase
- add separate domains.models.HostingDomain to allow for generic external
  domains
- add new hostingpackages.models.CustomerHostingPackageDomain to assign hosting
  domains to hosting packages

gnuviechadmin/domains/migrations/0002_auto_20150124_1909.py

@@ -0,0 +1,46 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+import django.utils.timezone
+from django.conf import settings
+import model_utils.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('domains', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='HostingDomain',
+            fields=[
+                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
+                ('created', model_utils.fields.AutoCreatedField(default=django.utils.timezone.now, verbose_name='created', editable=False)),
+                ('modified', model_utils.fields.AutoLastModifiedField(default=django.utils.timezone.now, verbose_name='modified', editable=False)),
+                ('domain', models.CharField(unique=True, max_length=128, verbose_name='domain name')),
+                ('customer', models.ForeignKey(verbose_name='customer', blank=True, to=settings.AUTH_USER_MODEL, null=True)),
+                ('maildomain', models.OneToOneField(null=True, to='domains.MailDomain', blank=True, help_text='assigned mail domain for this domain', verbose_name='mail domain')),
+            ],
+            options={
+                'verbose_name': 'Hosting domain',
+                'verbose_name_plural': 'Hosting domains',
+            },
+            bases=(models.Model,),
+        ),
+        migrations.AddField(
+            model_name='maildomain',
+            name='customer',
+            field=models.ForeignKey(verbose_name='customer', blank=True, to=settings.AUTH_USER_MODEL, null=True),
+            preserve_default=True,
+        ),
+        migrations.AlterField(
+            model_name='maildomain',
+            name='domain',
+            field=models.CharField(unique=True, max_length=128, verbose_name='domain name'),
+            preserve_default=True,
+        ),
+    ]