fix customize layout sizing

private_includes/base/basic_format_and_style_settings.ily

@@ -79,6 +79,11 @@ generalLayout = \layout {
   }
 }
 
+#(define (customized-layout base-layout)
+   (let
+     ((custom-size (ly:output-def-lookup base-layout 'size #f)))
+     (if custom-size (layout-set-staff-size custom-size))))
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%% kleine Helferlein: