Using custom JACK server name

In case you want to use JackTrip with JACK server that has non-default name (by default it is default), you need to set JACK_DEFAULT_SERVER environment variable for JackTrip.

1. Run jackd with --name flag:jackd --name myfancyserver ...
2. Run JackTrip with required environment variable set: JACK_DEFAULT_SERVER=myfancyserver jacktrip ...

This is useful when you want to isolate multiple JackTrip instances on single machine.