Merge branch 'en/test-selector'

Our test scripts can be told to run only individual pieces while skipping others with the "--run=..." option; they were taught to take a substring of test title, in addition to numbers, to name the test pieces to run. * en/test-selector: test-lib: reduce verbosity of skipped tests t6006, t6012: adjust tests to use 'setup' instead of synonyms test-lib: allow selecting tests by substring/glob with --run