Add error numbers to the exit codes so that readers can decode them
without having to use a separate utility. Organize exits by error code.
Mark up the error constants with the error constant macro, even though
this is really not very helpful because people will search for the error
code, the macro is explicitly for the constants and not the codes.

While where, align and alphabetize the options list as well, fix
misaligned padding in an example, and a one-sentance-per-line error.

MFC after:		3 days
Reported by:		Antranig Vartanian <antranigv@freebsd.am>
Differential Revision:	https://reviews.freebsd.org/D48470

Switch various flags from int -> bool.

kill(getpid(), foo) and raise(foo) are equivalent in this context, so
switch to the latter as a minor preference for readability.

Use proper signal fences instead of volatile for our SIGALRM handler.

Reviewed by:	kib (earlier version), des
Differential Revision:	https://reviews.freebsd.org/D51027

Reviewed by:	des
Differential Revision:	https://reviews.freebsd.org/D51026

This is useful to avoid having the command running twice in the face of
the admin terminating the process.  Notably, if the -p option is not in
use (or can't be used, e.g., because we can't open the file for writing)
then this provides a nice alternative where one simply needs to send a
SIGTERM to the lockf(1) process associated with the lock file to clean
it all up.

Reviewed by:	des
Differential Revision:	https://reviews.freebsd.org/D51025

A future change will add a -T flag to forward SIGTERM along to the
child before we cleanup and terminate ourselves.  Using a SIGCHLD
handler to do that with SIGTERM blocked only while the child is actively
being collected will enable us to safely do so without having to worry
that our pid is potentially invalid.

Add a test that concisely checks that the child's error is properly
bubbled up to the caller.

Reviewed by:	des, kib
Differential Revision:	https://reviews.freebsd.org/D51024

If we're going to hold the lock, it can be useful to scribble down the
pid that we spawned off to quickly associate the lock back to the
process that's keeping it open.

Reviewed by:	allanjude (previous version), des
Differential Revision:	https://reviews.freebsd.org/D51014

After building packages we have a number of new
and updated Makefile.depend files

Reviewed by:	stevek

This is a residual of the $FreeBSD$ removal.

MFC After: 3 days (though I'll just run the command on the branches)
Sponsored by: Netflix

The test launches lockf(1) in the background and races with it, so it
shouldn't be using atf_check to check that lockf won the race.

MFC after:	1 week

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by:		Netflix