support AAAA records

[buckelij]

This PR adds support for AAAA records that take the form *.v6-[ip]-[v6]-[addr].xip.test.

For example:

$ dig v6-fda9-6b94-9d5-4c-a3-df-57-b4.xip.test AAAA +short
fda9:6b94:9d5:4c:a3:df:57:b4
$ dig www.v6-fda9-6b94-9d5-4c-a3-df-57-b4.xip.test AAAA +short
fda9:6b94:9d5:4c:a3:df:57:b4
$ dig v6-fda9-6b94-9d5--2.xip.test AAAA +short
fda9:6b94:9d5::2

[vg]

Why not use the URL encoded from of :, which is %3A.

Also that would only work in the browser.

[buckelij]

Why not use the URL encoded from of :, which is %3A.

I don't think a % is a valid DNS hostname character. Also it's uglier than a - 😁

[stefansundin]

I just had some need for this, and it would be great if this PR could be merged and deployed. @sstephenson, any chance this could happen?

If that's not possible, then maybe we can spin this up on another host? But that feels like a less than ideal solution.

[pjsg]

Any possibility of getting this merged?