Optional short tests for filtering the DNS list

[GoogleCodeExporter]

What do you see?
In its current setup, namebench tests a number of dns resolvers regardless of 
how you would filter them after the benchmark is completed. The application 
sends many kinds of queries and this takes a very long time while you would 
just skip many of the dns resolvers regardless of how fast they are. 

What is the expected output?
We should be able to do some nxdomain hijacking test and/or censorship test 
before the rest of the benchmark is carried out. Especially when you use a 
different resolver just because of the censorship, sometimes most of the 
resolvers just doesn't connect (this is what happened in Turkey with the latest 
Twitter ban, very few resolvers managed to connect to twitter). So, if this 
kind of a function added in your application, after filtering out the dns 
resolvers that do not work for us, we can run the benchmark and the time it 
will take will be much shorter.

What version of the product are you using? On what operating system?
Namebench 1.3.1 on Win7

Original issue reported on code.google.com by memetinp...@gmail.com on 25 May 2014 at 10:45