Add CDN ping time result to NameBench HTML report for better understanding the quality of the DNS server

Dear Thomas,

You "NameBench" is really good! Thank you for your effort!

However, I find that the quality of a DNS server doesn't only rely on the speed of result return, but also the result itself.
For example a DNS respond each request in less than 10ms, but it always return the resolving result in US, so APAC/EU user will still find slow to access the internet. This is particular noticeable when accessing CDN server, such as akamai or cloudfront.

So I made this changes to your "NameBench" script. Currently it only shows the result of Min/Avg/Max result for each nameserver, and it's not reflected in the final sorted result, because I think the DNS response time and ping time to the CDN host cannot simply be added and compared.

If you like my idea, please just pull.
And feel free to contact me if you have any comment.

Thank you!

Cheers,
Roger