add inverse option to ministat

[John-Mark Gurney]

I have created a patch to invert the data passed into ministat.  It
is often easier to measure data in time (seconds) using /usr/bin/time
or another method, but often you like to think in per second, or
throughput which is the inverse.

Instead of having to massage the data, or know that below a certain
percentage you can just flip the sign, provide this, and you'll now
convert to x per second, giving you an easier comparision for talking.

Review: https://reviews.freebsd.org/D3084

Thanks.

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."