[avahi] Behaviour with two interfaces.

[Peter Onion]

When I connected my laptop to my network today I forgot to turn off the
wireless interface.  I have a combined Wireless AP/Router/Hub/ADSL Modem
which forwards packets between it's wireless and wired intrerfaces.  So
in effect the laptop had two interfaces on the same network.  All the
services it advertised appeared twice which really confused some of my
client code which only expect to see one instance of a service type on
the network !   I'm going to have to rewrite some of my code to handle
this situation.

Peter