Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r250303:
Remove includes for old versions of FreeBSD.

Reviewed by: stass

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

- Add full support for header / data digests.
- Increase target limit from 4 to 64; this limit will be removed entirely
at a later time.
- Improve recovery from lost network connections.
- Fix some potential deadlocks and a serious memory leak.
- Fix incorrect use of MH_ALIGN (instead of M_ALIGN), which makes no
practical difference, but triggers a KASSERT with INVARIANTS.
- Fix some warnings in iscontrol(8) and improve the man page somewhat.

Submitted by: Daniel Braniss <danny@cs.huji.ac.il>
Sponsored by: Dansk Scanning A/S, Data Robotics Inc.

Big update to the iSCSI initiator code. Highlights include IPv6 support,
many bugs fixes, many more performance improvements.

Submitted by: Danny Braniss

M sbin/iscontrol/iscsi.conf.5
M sbin/iscontrol/iscontrol.8
M sbin/iscontrol/iscontrol.h
M sbin/iscontrol/config.c
M sbin/iscontrol/fsm.c
M sbin/iscontrol/login.c
M sbin/iscontrol/pdu.c
M sbin/iscontrol/misc.c
M sbin/iscontrol/auth_subr.c
M sbin/iscontrol/iscontrol.c
M sys/dev/iscsi/initiator/isc_cam.c
M sys/dev/iscsi/initiator/iscsi.h
M sys/dev/iscsi/initiator/isc_soc.c
M sys/dev/iscsi/initiator/iscsi_subr.c
M sys/dev/iscsi/initiator/iscsivar.h
M sys/dev/iscsi/initiator/isc_subr.c
M sys/dev/iscsi/initiator/iscsi.c
M sys/dev/iscsi/initiator/isc_sm.c

Fix typo.

Submitted by: danny at cs.huji.ac.il (author)

Update fix from rev 1.2.

Submitted by: danny at cs.huji.ac.il (author)
MFC after: 1 week

Fix a bug in hexadecimal formatting of the CHAP digest: bytes >= 0x80
were formatted as 0xff, causing the authentication to fail.

Reviewed by: scottl
MFC after: 1 week

Introduce Danny Braniss' iSCSI initiator, version 2.0.99. Please read the
included man pages on how to use it. This code is still somewhat experimental
but has been successfully tested on a number of targets. Many thanks to
Danny for contributing this.

Approved by: re