Bring in NetBSD's vis as of 2021-06-21
Man page fixes, -M, -N and -S support for shell meta characters (all or some)
and no locale.
Discussed with: emaste@
Differential Revision: https://reviews.freebsd.org/D25358
match our import of the (un)vis(3) APIs.
This adds support for multibyte encoding and the -h and -m flags which
support HTTP and MIME encoding respectively.
PR: bin/175418
Obtained from: NetBSD