[tz] Dealing with Pre-1970 Data

[Garrett Wollman]

<<On Fri, 30 Aug 2013 17:36:37 -0700, Paul Eggert <eggert at cs.ucla.edu> said:

> That sounds reasonable.  Here's a draft of a disclaimer,
> along with a pointer to a discussion of how little
> we know even about solar time if we go back far enough,
> and if it weren't for those amazing Babylonian astronomers
> we'd know even less.  I've pushed this into the
> experimental repository.

I like this change.

I would also note that anyone who wants LMT for a particular zone can
calculate it from the coordinates given in zone.tab.

-GAWollman