daemon: fix equality operators on IPServiceParam and DTNTPServiceParam
daemon: actually write the right DiscoveryBeacon protocol version
daemon: better visual test for DiscoveryBeacon endianess
daemon: implement IPND draft 02

In ibrdtnd.conf, set discovery_version = 3 to enable this.

Currently, only UDP and TCP service types are specified in IPND Draft
02. For our other supported services (e-mail CLA, LoWPAN CLA, multiple
Datagram CLA variants, DHT name resolution, DTNTP), private service
types have been implemented like they seemed fit.