Warn & exit when no stats are to be gathered.

apachedex/__init__.py

@@ -406,6 +406,10 @@ def main():
   default_site = args.default
   if default_site is None:
     default_action = None
+    if not [None for _, x in site_list if x is not None]:
+      print >> sys.stderr, 'None of --default, --erp5-base and --base were ' \
+        'specified, nothing to do.'
+      sys.exit(1)
   else:
     default_action = partial(GenericSiteStats, prefix=0)
   infile_list = args.logfile