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)

Resolve merge conflicts.

Fixed misspellings of 0 as NULL. Fixed some nearby style bugs.

Fix merge conflicts, and because this still has a zillion warnings,
protect the build with a WARNS=2.

Fix the build.

$Id$ -> $FreeBSD$

Many places in the code NULL is used in integer context, where
plain 0 should be used. This happens to work because we #define
NULL to 0, but is stylistically wrong and can cause problems
for people trying to port bits of code to other environments.

PR: 2752
Submitted by: Arne Henrik Juul <arnej@imf.unit.no>

Add prototypes, usage(). Use err(3).

Tom Gray's new tip changes to support a modem capabilities database and
fixes to many assorted bugs and misfeatures.
Submitted by: Tom Gray - DCA <dcasba@rain.org>