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

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Implement RFC3442, the Classless Static Route option.

The original DHCP specification includes a route option but it supports
only class-based routes. RFC3442 adds support for specifying the netmask
width for each static route. A variable length encoding is used to minimize
the size of this option.

PR: bin/99534
Submitted by: Andrey V. Elsukov <bu7cher@yandex.ru>
Reviewed by: brooks

Add a $FreeBSD$ tag missing after the original import. Note that this
file isn't actually installed; the one in src/etc is.

This commit was generated by cvs2svn to compensate for changes in r147072,
which included commits to RCS files with non-trunk default branches.

Import the OpenBSD dhclient as shipped with OpenBSD-3.7 (the tag
OPENBSD_3_7).