iostat patch: Add dillon's systat changes to iostat

[Matthew Dillon]

:for easier reviewing, inline:
:
:diff --git a/usr.sbin/iostat/iostat.c b/usr.sbin/iostat/iostat.c

    For some reason the patch command on that diff file fails on every chunk,
    not sure why.

    In anycase, I see where it is headed.  I think we might have an issue
    with too much information reducing the number of devices which can be
    displayed, so I'd like to suggest some other changes:

    * Provide options for various modes, with the default being the old
      (KB/t, tps, MB/s) tuple, so the output can remain compact.
      I recommend one that does (tps, MBr/s, MBw/s).

    * Maybe we can remove the tty statistics and add aggregate or
      primary interface network statistics.  Nobody cares about tty
      statistics any more but it would be kinda cool to see network
      stats there mixed with the disk stats.

    I am considering removing the tps/r, tps/w from systat -vm 1 and
    just having tps, but keeping MBs/r and MBs/w.  I think people will
    get more out of an aggregate tps stat.  Then for systat -vm 1
    we would have:  (KB/t, tps, MBs/r, MBs/w) (I should rename those to
    MBr/s and MBw/s I guess too).


						-Matt