Good thing I tried it after merging #5, because it did not work as written.
A CLI option can be TopLevelItem, not a subclass (apparently).
Also some other fixups:
Need not be serializable.
Printing to System.out is useless; you need to use CLICommand.stdout.
A meta var for --dump-build-number is meaningless since it takes no arguments.
Making --result be successful by default.
Fixing documentation of --display.
[maven-release-plugin] prepare release external-monitor-job-1.2