Handle response format changes noisily about whois

[weppos]

You're right DerGuteMoritz.

The problem is that, currently, there isn't a real validation system in place to make sure we're dealing with the expected response format.

For maintainers that includes the format version in the response, like denic does, I'm planning to add a validation system in the future. Talking about denic, they just introduced a major problem: they are skipping format version when a domain is invalid or unavailable, which introduces additional complexity.

On the other side, I already started to add a more restrictive validation in some circumstances. For instance, some parsers already raises an exception when they found an unknown #status string, instead of silently returning a default value.

However, this is not a small issue and I need more time to find a comprehensive solution and apply it.