create directories for new users

- use new file tasks to create SFTP and mail base directories for users
- use json serializer as default
- remove TaskResult classes that don't provide any significant benefit

gnuviechadmin/osusers/migrations/0002_auto_20141226_1456.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('osusers', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.DeleteModel(
+            name='DeleteTaskResult',
+        ),
+        migrations.RemoveField(
+            model_name='grouptaskresult',
+            name='group',
+        ),
+        migrations.DeleteModel(
+            name='GroupTaskResult',
+        ),
+        migrations.RemoveField(
+            model_name='usertaskresult',
+            name='user',
+        ),
+        migrations.DeleteModel(
+            name='UserTaskResult',
+        ),
+    ]