spin 1.73

I removed a directory from my web site this afternoon, ran into spin's lack of support for deleting removed directories, and took a moment to fix that. It requires switching from find to finddepth, and I'm not sure what version of File::Find introduced that interface, so it may require a newer version of Perl than 5.005 now. I didn't go back and check.

I also mentioned that dependency handling doesn't work ideally with \sitemap and \include, added better documentation around \id and the Subversion Id expansion, and made a few other documentation improvements.

You can get the latest version from my web tools distribution page.