Seperate status timer setup from disk util timer

Seperate status timer setup from disk util timer

It's still the same timer and shared, but move it out of
diskutil so we get proper status reporting on non-Linux.

We also need to rearm the signal handlers on each signal.
Move this to sigaction() next.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>