Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Fix the case where the utility is being used to run a command directly,
this is a regression introduced with r228917.

PR: bin/154042
Submitted by: Bugs Beastie <bugsbeastie gmail.com>
MFC after: 1 week

- Fail when the utility is not invoked as rtprio nor idprio.
- use warnx() to tell the user whether a process is running in normal,
idle or realtime priority. with the old code it would have been possible
for another process to send data to stdout between
printf("%s: ", p);
and
printf("* priority\n");
and thus break the formatting.
- 'rtprio 10 -0' triggeres non-intuitive behavior. It would first set the
priority of itself to 10 *and* would then try to execute '-0'. Of course,
setting the priority of [id|rt]prio itself doesn't make a lot of sense,
but it is intuitive compared to the previous behavior.
- 'rtprio -t --1' will actually pass over the '-1' to rtprio(). Now
invoking rtprio like this will catch the wrong usage before passing
over the invalid argument to rtprio().
- Garrett Cooper suggested to add further diagnostics where the failure
occures, if execvp fails.

PR: bin/154042
Submitted by: arundel
MFC after: 1 month

Use errx() instead of err() in parseint. There is usually no interesting
information in errno.

Noted by: Garrett Cooper <yanegomi gmail com>
MFC after: 1 week

Make the parsing of the integer arguments for rtprio(1)/idprio(1) stricter.
Style.

Based on submission by: Eitan Adler <lists eitanadler com>, keramida
Reviewed by: jhb, keramida
MFC after: 1 week

add FBSDID

Return exit value 0 on success when PID is specified.

$Id$ -> $FreeBSD$

PR: 7489
Submitted by: Jos.Backus@nl.origin-it.com
Correct execvp fail message in current

Treat RTP_PRIO_FIFO the same as RTP_PRIO_REALTIME for status display.

Use err(3). Sync usage string and man page.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

"idle priority" support. Based on code from Henrik Vestergaard Draboel,
but substantially rewritten by me.

rtprio(1) utility to modify realtime priority of a process.

Submitted by: Henrik Vestergaard Draboel