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)

- Commit work from libprocstat project. These patches add support for runtime
file and processes information retrieval from the running kernel via sysctl
in the form of new library, libprocstat. The library also supports KVM backend
for analyzing memory crash dumps. Both procstat(1) and fstat(1) utilities have
been modified to take advantage of the library (as the bonus point the fstat(1)
utility no longer need superuser privileges to operate), and the procstat(1)
utility is now able to display information from memory dumps as well.

The newly introduced fuser(1) utility also uses this library and able to operate
via sysctl and kvm backends.

The library is by no means complete (e.g. KVM backend is missing vnode name
resolution routines, and there're no manpages for the library itself) so I
plan to improve it further. I'm commiting it so it will get wider exposure
and review.

We won't be able to MFC this work as it relies on changes in HEAD, which
was introduced some time ago, that break kernel ABI. OTOH we may be able
to merge the library with KVM backend if we really need it there.

Discussed with: rwatson

Revert most part of 200420 as requested, as more review and polish is
needed.

Remove unneeded header includes from usr.bin/ except contributed code.

Tested with: make universe

Include param.h instead of types.h before user.h so that the nested
include of param.h can be removed from audit.h.

MFC after: 3 weeks

WARNS fixes: mainly constness and avoid comparing signed with
unsigned by making array indicies unsigned. Also note one or two
unused parameters.

Add procstat(1), a process inspection utility. This provides both some
of the missing functionality from procfs(4) and new functionality for
monitoring and debugging specific processes. procstat(1) operates in
the following modes:

-b Display binary information for the process.
-c Display command line arguments for the process.
-f Display file descriptor information for the process.
-k Display the stacks of kernel threads in the process.
-s Display security credential information for the process.
-t Display thread information for the process.
-v Display virtual memory mappings for the process.

Further revision and modes are expected.

Testing, ideas, etc: cognet, sam, Skip Ford <skip at menantico dot com>
Wesley Shields <wxs at atarininja dot org>