Grant permission to run table-info functions to public

This is needed as a way to migrate from versions < 0.2.0
See #36

scripts-available/CDB_ColumnNames.sql

@@ -11,3 +11,6 @@ AS $$
          
 $$ LANGUAGE SQL;
 
+-- This is to migrate from pre-0.2.0 version
+-- See http://github.com/CartoDB/cartodb-postgresql/issues/36
+GRANT EXECUTE ON FUNCTION CDB_ColumnNames(REGCLASS) TO PUBLIC;