Update dnssd.lua and related scripts

* Structured output
* Fix adding new targets: was adding the multicast address, not the
  discovered unicast address.
* Extract service name and host name from responses
* broadcast-dns-service-discovery now lists services under each unicast
  address instead of under the single multicast/broadcast address.

scripts/broadcast-dns-service-discovery.nse

@@ -1,5 +1,6 @@
 local dnssd = require "dnssd"
 local stdnse = require "stdnse"
+local oops = require "oops"
 
 description=[[
 Attempts to discover hosts' services using the DNS Service Discovery protocol.  It sends a multicast DNS-SD query and collects all the responses.
@@ -50,8 +51,5 @@ action = function()
   local helper = dnssd.Helper:new( )
   helper:setMulticast(true)
 
-  local status, result = helper:queryServices()
-  if ( status ) then
-    return stdnse.format_output(true, result)
-  end
+  oops.output(helper:queryServices())
 end

scripts/dns-service-discovery.nse

@@ -61,7 +61,7 @@ action = function(host, port)
   if ( status ) then
     -- set port to open
     nmap.set_port_state(host, port, "open")
-    return stdnse.format_output(true, result)
+    return result
   end
 end