Various fixes for auxiliary/spoof/llmnr/llmnr_response and related stuff

* Converts to use Net::DNS instead of hardcoded packets. This incidentally gives us the ability to respond to AAAA requests as well as A.

* Fixes problems when recvfrom returns a mapped address like "::ffff:192.0.2.1".  This happens on Linux, but I don't know exactly what the cause is. 

* Makes it only listen on the interface we're sending packets from so we don't end up putting packets on the wrong wire

## Verification
 
- [x] Set up `llmnr_response` on a VMWare NAT interface with the host's NAT address for `SPOOFIP`
- [x] Run `ping wpad` from a Windows (Vista+) VM with a NAT interface
- [x] See the ping hit our spoofed address
- [x] Run `ping wpad` from a Windows VM with a host-only interface
- [x] See the ping fail to resolve