[tz] Version in zoneinfo files?

[Paul Eggert]

lester at lsces.co.uk wrote:
> The version number is essential data

It's not essential to put the version number into zic's output, as the tz 
project has been operating successfully for decades without doing so. Although 
there are benefits to having a version number in the data, there are costs too, 
and it's not clear which is greater.

If one needs a unique number to briefly identify a data file, one can use a hash 
function of the data. This should suffice for tzdist's needs, so that tzdist 
shouldn't require a version number in the data.