Interface searching, AeronUri prototype, local address resolution and logging channel creation

- Interface searching works
- AeronUri is not yet merged in, so UdpChannel uses the existing URI format, but also support parameters, e.g. `subnetPrefix=24`
- Channels are logged on creation to the EventLogger.  New code CHANNEL_CREATION and is added into the admin set of events.
- UdpChannel applies more checks to the validity of the interfaces, especially for multicast.  Fail early with useful errors is the goal.