[DGD] Implementing hotbooting

[Shentino]

I'm working on a hotboot patch for dgd that will let it hotboot just like hydra.

So far I have the LPC side working and have added the handling
required to track it.  Now I need to do the driver side and actually
make it work.

(experimenters are free to pull from the hotboot branch of my github
repo on dgd)

So far, what I think to do is check for a snapshot also being
triggered, then when we're done and ready to shut down, if a hotboot
is requested push all state we need to a temporary buffer (open ports,
open connections).  Then exec and reattach to all the open stuff we
stashed in the buffer.

Am I missing anything?