"cut -f 2-0" now fails; before, it was equivalent to "cut -f 2-"

"cut -f 2-0" now fails; before, it was equivalent to "cut -f 2-"
Also, diagnose the '-' in "cut -f -" as an invalid range, rather
than interpreting it as the unlimited range, "1-".
* NEWS: Mention these changes.
* src/cut.c (set_fields): Don't interpret an accumulator "value"
of 0 as an unspecified range endpoint.
Give better diagnostics.
Adjust a comment so that it is true also for 64-bit size_t.
* tests/cut/Test.pm: Add tests for the above.