Let's keep dnsperf as there are local modifications and some of the system
tests will use it if it's present.

The others I'm fine with; the only reason they're still there now is the
dumb swamp I stepped in last time I tried to remove them, which I will 
explain with the following dramatization:

Act 1

EVAN: We should have a web page that links to these packages instead
of including them in contrib.

PRESIDENT: If we do that, it might be seen as *recommending* that
software. We would incur legal risk.

EVAN: Well, including them in contrib, which we already do, would seem to
be "recommending" it too, but whatever, just write a disclaimer.

PRESIDENT: So mote it be. I call upon our lawyer to issue a disclaimer!

LAWYER: [apparently takes four-year vow of silence]

NOW-FORMER PRESIDENT: [exits, pursued by a bear]

Act 2

ONDREJ: We should have a web page that links to these packages instead
of including them in contrib.