This allows someone to host a static site by pointing a TXT record at their
content in IPFS, and a CNAME record at an IPFS gateway.

Note that such a setup technically violates RFC1912 (section 2.4; "A CNAME
record is not allowed to coexist with any other data."), but tends to work in
practice.

We may want to consider changing the DNS->IPFS resolution scheme to allow this
scenario to be RFC-compliant (e.g. store the mapping on a well-known subdomain
to allow CNAME records on the domain itself).

License: MIT
Signed-off-by: Kevin Wallace <kevin@pentabarf.net>