[dns-operations] Client retry behavour?

[Paul Vixie]

> I've sometimes wondered why resolv.conf doesn't have an option to 
> randomise the initial query order of nameservers.  But then down that path 
> lies the feeping creaturism of 'primary_nameserver' and its ilk.

there's RES_ROTATE but that's as far as i got before we closed the door on
resolv.conf and decided that options belonged in lwresd which does have this
kind of feeping creaturism in it.