Log resolvers that are poisoning responses to a separate log file.

[vortexau]

This tool is good at detecting resolvers that exist simply to poison Internet DNS traffic, however the initial form of the tool simply discards this information as it is not useful in the core usage of the tool.

Performing further research on the blocked servers would be interesting, so it would be handy to optionally log these to a separate file for further research.

Over time it would be possible to build an exclusion list for known-bad resolvers that can simply be ignored.