Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r248303:

Replace our (un)vis(1) commands with implementations from NetBSD to
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

Replace our (un)vis(1) commands with implementations from NetBSD to
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

Vendor import of NetBSD's vis(1) at 2013-02-21