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

Style tweak.

Approved by: re (kib)
MFC after: 3 days

If the label being printed by getpmac(8) is empty, then don't print a
carriage return.

Obtained from: TrustedBSD Project
MFC after: 3 days

WARNS?=6 cleanup for [gs]et[fp]mac:
- Constify structure members that should not be changed
during process.
- Apply static where needed
- signed/unsigned madness
- Bump WARNS?= levels from 2 to 6

(this is a diff reduction for a subsequent commit against these
Makefile's)

Userland signed char fixes for PPC build. Problems were using a char
return for getopt() and comparing to -1, ditto with fgetc() and EOF,
and using the kg_nice value from <sys/user.h>

Submitted by: Stefan Farfeleder <stefan@fafoe.narf.at>
Reviewed by: obrien, bde (a while back)
Tested lightly on: ppc, i386, make universe

Introduce simple command line tools to manage MAC labels on processes and
files. Basically wrappers for mac_{get,set}_{file,link,pid,proc}(3).
Man pages to be updated shortly.

Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories