Updated canaryd, ended up starting fresh and pulling things in, rather

than jamming more stuff into the old one.  Most of the code came from
the previous version of canaryd, the cpu broker (process accounting),
and the janosvm (network interface accounting).  Its missing some
features of the old one, but those can be incorporated without too
much trouble.

Changes:

  Designed to permanently run on the pnodes:  it waits for START events
    before it begins recording.  However, I haven't done the work
    necessary to have it always startup on the pnodes.

  No more exec'ing: process stuff is taken from "/proc", and network
    interface stats are pulled from getifaddrs(3).

  Fixed some minor bugs: A typo caused the real-time priority to not
    be set, use setitimer instead of sleep to get more accurate
    spacing between samples.