bug#61467: Don't assume short/long options for error messages

[Dan Jacobson]

$ sort --human-numeric-sort -nr
sort: options '-hn' are incompatible

Say instead:
sort: options --human-numeric-sort (-h), and --numeric-sort (-n), are 
incompatible.

Else some projects might be delayed by days, as some people need to
email other people to ask...

"Can't blame me. That's not what I typed. I typed -nr, not -hn. Sue me."