transfer class's file_exists() method fails on some platforms

On some platforms the file_exists() method may fail because the _ls() method may or may not return the path in each element. Also, if the path is returned, the directory separators may be mixed. This occurs on IIS7 using fsock and MS-DOS PATH styles.

Stripping the listing of the path is probably the easiest way to ensure it will work on all platforms.

Regards
Mike Marchand