Replace pwgen 1 with pwgen 2. The latter is a continuation of the former
by a different author, with some serious bugs fixed. We were pretty much
the only OS that still shipped pwgen 1, and for good reason: due to the
way it implements phoneme equivalence and the way it tracks the length of
the generated string, it only works correctly 16% of the time. This was
not possible to fix without a major rewrite, which is precisely what the
author of pwgen 2 did.
Discussed with both maintainers and #bsdports.