allow "name" arg to "txt" record
v0.203

        - make it possible to emit MX records without an IP (no_ip => 1)
        - change the way that fallback/other network PTRs are generated
        - update test utilities to deal with ' lines (TXT records) in tinydns
        - allow "name" argument to "txt" record in TinyDNS to avoid needing a
          node