kern/167321: Implement sysctl to control kernel accounting log messages (e.g. acct(2))

[Jeremy Chadwick]

Note for readers/committer: hold off on doing anything quite yet.
I'm in conversation with John Baldwin (jhb@) about this issue, and
he's given me a patch (to both the periodic script and the kernel)
that may rectify the entire "excess logging" situation entirely.

Will report back in the next few weeks (have health things/doctors
visits going on, so please be patient).  Thanks.

-- 
| Jeremy Chadwick                                   jdc at koitsu.org |
| UNIX Systems Administrator                http://jdc.koitsu.org/ |
| Mountain View, CA, US                                            |
| Making life hard for others since 1977.             PGP 4BD6C0CB |