* install-rpm, install-tarfile, spewrpmtar.php3, spewrpmtar.in: Pumped
  up even more! The db file we store in /var/db now records both the
  timestamp (of the file, or if remote the install time) and the MD5
  of the file that was installed. Locally, we can get this info when
  accessing the file via NFS (copymode on or off). Remote, we use wget
  to get the file, and so pass the timestamp along in the URL request,
  and let spewrpmtar.in determine if the file has changed. If the
  timestamp it gets is >= to the timestamp of the file, an error code
  of 304 (Not Modifed) is returned. Otherwise the file is returned.

  If the timestamps are different (remote, server sends back an actual
  file), the MD5 of the file is compared against the value stored. If
  they are equal, update the timestamp in the db file to avoid
  repeated MD5s (or server downloads) in the future. If the MD5 is
  different, then reinstall the tarball or rpm, and update the db file
  with the new t...