Refactor: split code into several django apps (we call them modules).

dav_base/management/commands/list_modules.py

@@ -0,0 +1,17 @@
+from django.conf import settings
+from django.core.management.base import BaseCommand
+
+
+class Command(BaseCommand):
+    help = 'List enabled modular apps in django-dav installation.'
+
+    def add_arguments(self, parser):
+        pass
+
+    def handle(self, *args, **options):
+        paragraphs = []
+        config = settings.MODULE_CONFIG
+        for obj in config.modules.values():
+            paragraphs.append(str(obj))
+        output = '\n'.join(paragraphs)
+        self.stdout.write(output)