+ * callback function, especially interface and protocol. The protocol
+ * argument specifies the protocol (IPv4 or IPv6) to use as transport
+ * for the queries which are sent out by this resolver. The
+ * aprotocol argument specifies the adress family (IPv4 or IPv6) of
+ * the address of the service we are looking for. Generally, on
+ * "protocol" you should only pass what was supplied to you as
+ * parameter to your AvahiServiceBrowserCallback. In "aprotocol" you
+ * should pass what your application code can deal with when
+ * connecting to the service. Or, more technically speaking: protocol
+ * specifies if the mDNS queries should be sent as UDP/IPv4
+ * resp. UDP/IPv6 packets. aprotocol specifies whether the query is for a A
+ * resp. AAAA resource record. */