[tz] Getting current tzdb version in use

[Robert Elz]

    Date:        Fri, 20 Jul 2018 11:35:59 -0700
    From:        Paul Eggert <eggert at cs.ucla.edu>
    Message-ID:  <84d13601-c08a-ede3-bf8a-22f290c8ae43 at cs.ucla.edu>

  | Admittedly it's not a big deal, but if we're upgrading tzdata in 5 billion 
  | mobile devices ten times per year and saving 50 kB per upgrade, [...]

Hopefully I did not say or imply, that the compressed file wasn't useful.
All I think I said, or all I intended to say, was that we do not use it in
NetBSD, and have no current plans to do so,   You don't need to defend it.

kre