[dns-operations] fast-dns-query tool

[hua peng]

I have the interests to know it. thanks.

> i have been playing with what i call my 'fast dns query' tool for just over a year but recently made it more user-friendly (not by much).
>
> This lets you drop in a list of (IPv4) addresses and send out the same DNS query to all of them and post-process the results.
>
> Is this something the community would find valuable to be released?  It can run through the list of "well behaved dns servers" (~4-7mil) in ~3-4 minutes.