Synchronise with FreeBSD:

Synchronise with FreeBSD:

Treat filenames as multibyte character strings (according to the current
LC_CTYPE setting) when determining which characters are printable.
This is an often-requested feature.

Use wcwidth() to determine the number of column positions a character
takes up, although there are still a few places left where we assume
1 byte = 1 column position, e.g. line-wrapping when handling the -m option.

The error handling here is somewhat more complicated than usual: we do
our best to show what we can of a filename in the presence of conversion
errors, instead of simply aborting.