From http://www.jwz.org/xscreensaver/xscreensaver-5.34.tar.gz
[xscreensaver] / OSX / update-thumbnail.pl
2014-11-16 Zygo BlaxellFrom jwz.org/xscreensaver/xscreensaver-5.31.tar.gz
2013-11-11 Zygo BlaxellFrom jwz.org/xscreensaver/xscreensaver-5.23.tar.gz
2013-07-16 Zygo BlaxellFrom jwz.org/xscreensaver/xscreensaver-5.22.tar.gz
2013-02-08 Zygo BlaxellFrom jwz.org/xscreensaver/xscreensaver-5.20.tar.gz
2013-02-08 Zygo BlaxellFrom jwz.org/xscreensaver/xscreensaver-5.19.tar.gz