Support repo-based makecatalogs (#1012)

* if repo plugin has a makecatalogs method defined, use it instead

* pass options and output_fn to repo makecatalogs method

code/client/makecatalogs

@@ -95,7 +95,10 @@ def main():
         exit(-1)
 
     # Make the catalogs
-    errors = makecatalogslib.makecatalogs(repo, options, output_fn=print)
+    try:
+        errors = repo.makecatalogs(options, output_fn=print)
+    except AttributeError:
+        errors = makecatalogslib.makecatalogs(repo, options, output_fn=print)
 
     if errors:
         # group all errors at the end for better visibility