Hiya,
Very helpful little plugin this. Thank you for that!
Just though I'd let you know that with WP_DEBUG on, it produces a lot of warnings as it will try and treat directories as files.
This can easily be fixed. Just change line 64:
if( file_exists( $realfile ) ){
to:
if( file_exists( $realfile ) && !is_dir( $realfile ) ){
Hope this helps & keep up the good work!
Smile,
Juliette