Making Modoboa a standard django application.

see #245

example/manage.py

@@ -0,0 +1,14 @@
+#!/usr/bin/env python
+from django.core.management import execute_manager
+import imp
+try:
+    imp.find_module('settings') # Assumed to be in the same directory.
+except ImportError:
+    import sys
+    sys.stderr.write("Error: Can't find the file 'settings.py' in the directory containing %r. It appears you've customized things.\nYou'll have to run django-admin.py, passing it your settings module.\n" % __file__)
+    sys.exit(1)
+
+import settings
+
+if __name__ == "__main__":
+    execute_manager(settings)