Add the following flags to rsync:
* `-H, --hard-links preserve hard links`
* `-A, --acls preserve ACLs (implies --perms)`
* `-X, --xattrs preserve extended attributes`
(i.e., the preservation options not already implied by -a).
Also exclude the special paths that do not make sense to rsync, because
reading the extended attributes from those can cause errors, at least
with SELinux enabled.
This fixes installation of Fedora systems with SELinux enabled.