MFC r235297, r235316:

MFC r235297, r235316:

Add a -v and -N option to kenv(1), so it can be more easily used in
scripts the way sysctl(8) is.  The -N option, like in sysctl(8),
displays only the kenv names, not their values.  The -v option prints an
individual kenv variable name with its value as name="value".  This is
the inverse of sysctl(8)'s -n flag, since the default behaviour of
kenv(1) is already like sysctl(8) -n.

git-svn-id: svn://svn.freebsd.org/base/stable/9@236118 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f