Bug 182521

As part of my diploma thesis at the engineering department, I modified
the audit subsystem to return the lwpid of the audited thread in the
subject token of an audit record. Normally, the kernel produces records
which only contain the sid and pid; this makes the process of separating
record streams coming from different threads of a multithreaded application
a hard (or even impossible) task. Hopefully, the attached patch can be
used to bypass this limitation, however it comes at a price; modifications
are required in kernel land as well as in userland. I understand that
deciding to merge these changes in the FreeBSD code base is a hard choice
for many reasons (quality standards, number of affected components and so
on), nevertheless, the patch may be helpful for people building tools on
top of the audit mechanism :)

The patch also adds missing AUDIT_ARG_*() macros in certain network related
system calls like bind().

If you have any questions/suggestions, I can be reached at the mail
address specified in this message. Alternatively, you can talk to my
supervisor who is also a member at the FreeBSD forums: George Mamalakis
<mamalos@eng.auth.gr>

Fix: Patch attached with submission follows: