Some 64-bit cleaning for archivers/zoo - one year later

[Rhialto <rhialto%falu.nl@localhost>]

See http://www.netbsd.org/cgi-bin/query-pr-single.pl?number=38449 ,
which I wrote a full year ago.

I gave a ready-to-commit fix.

In the mean time it still isn't in pkgsrc-2009Q1 - which seems to exist
but without any announcement anywhere.

-Olaf.
-- 
___ Olaf 'Rhialto' Seibert    -- You author it, and I'll reader it.
\X/ rhialto/at/xs4all.nl      -- Cetero censeo "authored" delendum esse.