The implicit behavior of pulling it out of the classpath seemed not
to work properly and could be thrown off by other things on the
classpath also providing the properties file. This guarantees that
our settings stick.
A default of 0 means that if you deploy two NixOS boxes with the default
configuration, the second will fail because the brokerId was already in
use. Using -1 instead tells it to pick one automatically at first start.
- add missing types in module definitions
- add missing 'defaultText' in module definitions
- wrap example with 'literalExample' where necessary in module definitions
JVMs exit with exit code 128+signal when receiving a (terminating)
signal. This means graceful termination of a JVM will result in 143, so
add that to `SuccessExitStatus` in systemd service unit.