Changed django-admin.py to display help if invoked with no arguments. Thanks, sopel

git-svn-id: http://code.djangoproject.com/svn/django/trunk@1173 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/bin/django-admin.py

@@ -77,7 +77,7 @@ def main():
     try:
         action = args[0]
     except IndexError:
-        print_error("An action is required.", sys.argv[0])
+        parser.print_usage_and_exit()
     if not ACTION_MAPPING.has_key(action):
         print_error("Your action, %r, was invalid." % action, sys.argv[0])
     if action in ('createsuperuser', 'init', 'validate'):