[tz] Troll and zic warnings

[Paul Eggert]

Arthur David Olson wrote:
> It may be useful to have zic warn when producing a binary with more than
> 1200 transition times; one possibility is attached (and appears below with
> tabs mangled).

Thanks, I unmangled the indentation and pushed it into the experimental 
repository as commit af89d6b3626219bcbd46a1d94ba9b2b76fd59cfb.