Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Make tip exit if the device disappears, for instance when unplugging
or resetting USB serial devices.

Somebody[tm] should rewrite tip(1) to use two thread instead of two
processes or maybe even use that new-fangled "select(2)" or positively
futuristic "poll(2)" system call.

Flush the scriptfile whenever we see a non-graphical character to get
more real-time logging, without forcing a write(2) on every single
character.

Fix compilation warnings (up to level 3).

Resolve merge conflicts.

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

Fix the build.

Use STD{ERR,IN,OUT}_FILENO instead of their numeric values. The
definitions are more readable, and it's possible that they're
more portable to pathalogical platforms.

Submitted by: David Hill <david@phobia.ms>

If the user exists abruptly, tip's "tipout" child can hang around
forever. Since the lock file doesn't get cleaned up, this prevents
other users from accessing the target device.

(phk adds: Man, this has been bugging me for YEARS!)

PR: 12528
Submitted by: Craig Leres leres@ee.lbl.gov
MFC after: 1 week

#include <errno.h> where needed. Kill extern int errno;.

Minor warnings in tip corrected.

$Id$ -> $FreeBSD$

Change from using sys/param.h and MAXPATHLEN to using limits.h and PATH_MAX
to avoid the NOFILE problem. Back out NOFILE kludge. Fix unexploitable
buffer overflow in tipout.c.
Reviewed by: millert@openbsd.org (tipout.c)
Submitted by: millert@openbsd.org (rest of idea)

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

We wouldn't want to kill init if our parent died...

Spotted by: davidg

Die if we get errors from the tty.

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>