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 227489:
- fix duplicate "a a" in some comments

Approved by: simon

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

Approved by: re (implicit)

Improve error reporting. Use corresponding error message when file to be
preprocessed is missing. Also suggest to use absolute pathname if -p option
is specified.

PR: bin/156653
MFC after: 2 weeks

Initialize co.use_set variable before parsing each new rule.

PR: bin/134975
MFC after: 2 weeks

Increase buffer size for the command line.

PR: bin/125370
Submitted by: sem
MFC after: 2 weeks

Whitespace fixes.

Checked with: md5, diff -w

fix a buffer overflow with large (100k+) number of input lines.

MFC after: 3 days

reduce diffs with the cross-platform version (windows needs
some extra initialization)

Bring in the most recent version of ipfw and dummynet, developed
and tested over the past two months in the ipfw3-head branch. This
also happens to be the same code available in the Linux and Windows
ports of ipfw and dummynet.

The major enhancement is a completely restructured version of
dummynet, with support for different packet scheduling algorithms
(loadable at runtime), faster queue/pipe lookup, and a much cleaner
internal architecture and kernel/userland ABI which simplifies
future extensions.

In addition to the existing schedulers (FIFO and WF2Q+), we include
a Deficit Round Robin (DRR or RR for brevity) scheduler, and a new,
very fast version of WF2Q+ called QFQ.

Some test code is also present (in sys/netinet/ipfw/test) that
lets you build and test schedulers in userland.

Also, we have added a compatibility layer that understands requests
from the RELENG_7 and RELENG_8 versions of the /sbin/ipfw binaries,
and replies correctly (at least, it does its best; sometimes you
just cannot tell who sent the request and how to answer).
The compatibility layer should make it possible to MFC this code in a
relatively short time.

Some minor glitches (e.g. handling of ipfw set enable/disable,
and a workaround for a bug in RELENG_7's /sbin/ipfw) will be
fixed with separate commits.

CREDITS:
This work has been partly supported by the ONELAB2 project, and
mostly developed by Riccardo Panicucci and myself.
The code for the qfq scheduler is mostly from Fabio Checconi,
and Marta Carbone and Francesco Magno have helped with testing,
debugging and some bug fixes.

Implement an ipfw action to reassemble ip packets: reass.

move a variable declaration to the beginning of the block
(unfortunately, it is far away; we need to pack this code in
a better way).

Start splitting the monster file in smaller blocks.

In this episode:
- introduce a common header with a minimal set of common definitions;
- bring the main() function and options parser in main.c
- rename the main functions with an ipfw_ prefix

No code changes except for the introduction of a global variable,
resvd_set_number, which stores the RESVD_SET value from ip_fw.h
and is used to remove the dependency of main.c from ip_fw.h
(and the subtree of dependencies) for just a single constant.