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)

Decrease to WARNS=3.

Clean up compilation warnings. Set WARNS=6 in Makefile.

PR: 71659
Submitted by: Dan Lukes <dan obluda cz>

Move common credential save and restore code into a separate file.
Improve credential handling in pt_file.c

Add a new pipe sub-namespace.
This allows us to:
- perform scatter gather operations without using temporary files,
- create non-linear pipelines, and
- implement file views using symbolic links.

File view idea by: Vassilios Karakoidas
Portalfs pointer by: John Ioannidis
MFC after: 1 month

style.Makefile(5):
Use WARNS?= instead of WARNS=.

Correct paths to mount sources.

Default to WARNS=2.
Binary builds that cannot handle this must explicitly set WARNS=0.

Reviewed by: mike

Rename (after a repo-copy) some mount(8) programs:

mount_fdesc -> mount_fdescfs
mount_null -> mount_nullfs
mount_portal -> mount_portalfs
mount_umap -> mount_umapfs
mount_union -> mount_unionfs

- FDESC, FIFO, NULL, PORTAL, PROC, UMAP and UNION file
systems were repo-copied from sys/miscfs to sys/fs.

- Renamed the following file systems and their modules:
fdesc -> fdescfs, portal -> portalfs, union -> unionfs.

- Renamed corresponding kernel options:
FDESC -> FDESCFS, PORTAL -> PORTALFS, UNION -> UNIONFS.

- Install header files for the above file systems.

- Removed bogus -I${.CURDIR}/../../sys CFLAGS from userland
Makefiles.

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

Set the default manual section for sbin/ to 8.

$Id$ -> $FreeBSD$

Add pt_tcplisten.c functionality, fix a few minor bugs

PR: kern/8793, misc/8796, kern/8797, kern/8798, kern/8050, kern/6758
Submitted by: Duncan Barclay <dmlb@ragnet.demon.co.uk>

Removed definition of _NEW_VFSCONF. The new vfsconf interface is now
the default.

Merge from Lite2 (use new getvfsbyname() and mount(2) interface)

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.

Use POSIX.2 regular expressions, get rid of libcompat.

And another absolute path -I :-<

Convert to our man installation style. Also fixed long-standing bug
in `fastboot'/`fasthalt' in which the interpreter would hang around
after `reboot' or `halt' is run, causing an irritating ``Killed'' message.

BSD 4.4 Lite sbin Sources

Note: XNSrouted and routed NOT imported here, they shall be imported with
usr.sbin.