Extend the wildcard detection support

[forgedhallpass]

Currently wildcard detection only works with a single domain. It would be nice to be able to support the following use-case:

cat root_domains | dnsx -rc servfail -w wordlist.txt -wd -r resolvers.txt

Steps:

1. filter based on the response code
2. brute-force
3. detect servers supporting wildcards
4. show all subdomains. Input domain that support wildcards, should appear only once. We could also mark them somehow.

[marcelo321]

@forgedhallpass would be cool to give as a flag the domains we want to filter, or just completely extend the wildcard filtering to all subs in the list.