I missed the beginning of this discussion because I wasn't subscribed,
but as soon as we unfreeze I'll add some code to clean up random tmp*
directories and also drop an index.html file in there so any junk that
might accumulate wouldn't be visible.
Unfortunately the deletion of the files doesn't actually remove them
from the web server, because the rsync call that copies them over
doesn't include --delete. I'll just fix it up after we unfreeze.