Modify nbd to handle network disconnections and transfers.

[bamos]

I'm not sure if this is necessary for the scope of the project,
but I think it would be interesting to modify the nbd server and client
to be resilient to network disconnects and transfers.
The current codebase will just crash.

This would be interesting as a standalone project so that
tech-savy people can share a block device between their phone
and computer.
All that's required is they rebuild the kernel for their rooted phone
with nbd enabled and run our application as root.
:-)