New option BIOHIST

[Paul Goyette <paul%whooppee.com@localhost>]

I had a couple of people tell me (after working on a rather thorny 
issue) that a new option BIOHIST (similar to KERNHIST/UVMHIST) might be 
useful to have.  So, I've gone and implemented it!  Diffs and sample 
output are available at www.netbsd.org/~pgoyette/

Code reviews would be appreciated, as well as any objective opinions on 
whether this should get committed.  (It would, of course, be turned off 
by default.)

+------------------+--------------------------+------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
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