Reconnecting an existing socket simply was not working; the Rust socket
did not expose any methods for reconnection, so I simply tried calling
connect() again. As near as I can tell, this was a no-op --- which makes
sense because both the sending and receiving threads had their own copy
of the Socket, and it's not clear what the synchronization behaviour
should have been.
Instead if the connection fails, we relay this information to the main
thread, wait for an acknowledgement, then simply destroy the listening
thread. The caller can then simply call `start()` again.
Sorry for so many things in one commit ... it was an iterative
process depending as I worked on BIP32 to get the other stuff
working. (And I was too lazy to separate it out after the fact.)
A breaking change by the array newtyping is that Show for Sha256dHash
now outputs the slice Show. You have to use `{:x}` to get the old hex
output.
This is a massive simplification, fixes a couple endianness bugs (though
not all of them I don't think), should give a speedup, gets rid of the
`serialize_iter` crap.