Add --except option (counterpart of --only).

Problem to solve

When testing/building repositories that have a large number of build goals/test goals it would be nice to have an --except option. This option would the opposite of using --only.

E.g for VIIA running all the unit tests takes a long period of time, therefore we have a separate test goal for each unit test, so that the tests can be compiled/executed individually using nitrile as well without having to adapt the test goal to do so.

When parallelizing our tests in CI using the new parallel option we want to run our unit tests/property tests but not execute our selenium tests (as these tests do not support parallelization).

However, in this case we would need to list all of these individual test goals using --only, which is very error prone (when adding a new test, the test has to be added to the list). The alternative would be to define a unit goal which depends on all the individual unit tests but this leads to the same problem.

Being able to specify --except=selenium would solve the problem without the drawbacks described above.

Proposal

Documentation

The --except option would have to be documented under nitrile test and nitrile build.