Enabling "disk free" report in Apache mod_dav

Apply this patch to Apache (use patch < dav-diskfree.patch in the sources directory) and install with mod_dav.

In FreeBSD, add the file to files/ in /usr/ports/www/apache22 and rename to patch-modules_dav_fs_repos.c.

Now, Apache properly reports back disk space still free when using WebDAV.