MFC r302471, r302473:

r302471:
Add RCS Id. Sort options in SYNOPSIS. Fix macro usage. Fix Dd.

Submitted by: wiz@NetBSD.org
Obtained from: NetBSD

r302473:
Sync usage between program and man page. Increase column width. [1]
Simplifay the usage() function
Replace errx/strerror with errc

Submitted by: wiz@NetBSD.org [1]
Obtained from: NetBSD