non-printable Unicode codepoints and invalid bytes with ASCII
question marks. No change for the SMALL version.
Using ideas developed by tedu@, phessler@, bentley@ and feedback from many.
OK yasuoka@ czarkoff@ sthen@.
- Correct sorting behaviour.
- Do multicolumn output in a way that's a more likely to line up evenly.
From D'Arcy J.M. Cain <darcy@druid.com>, NetBSD PR #2965.