UPD: dav_submission: included some feedback from manu.

dav_submission/apps.py

@@ -1,11 +1,11 @@
 # -*- coding: utf-8 -*-
 import os
 from django.conf import settings
-from django.core.exceptions import ImproperlyConfigured
 
 from dav_base.config.apps import AppConfig as _AppConfig, DefaultSetting
 
 DEFAULT_SETTINGS = (
+    DefaultSetting('enable_upload', True),
     DefaultSetting('upload_path', os.path.join(settings.BASE_VAR_DIR, 'lib', 'dav_submission', 'submissions')),
     DefaultSetting('max_files', 100),
     DefaultSetting('max_file_size_mib', 50),