Zoneserver mararc dns_port patch

[Sam Trenholme]

> Only to satisfy my curiousity, why '> 65530' and not '> 65535',
> otherwise known as 2^16 - 1?

I like having a "cushion of error" to stop things hitting the limits
of values; this helps minimize possible security problems.

I would like to thank Milan Kupcevic for submitting this patch; I will
look at it next week sometime.

William Summers provided me with a patch to compile MaraDNS under
OpenBSD last week; I finally integrated this patch in to the "HEAD
branch" of MaraDNS and it can be seen in a snapshot I uploaded
yesterday (20090219):

http://www.maradns.org/download/1.3/snap/200902

- Sam