ss-hw serves as the hardware interface for SmartShelf.  It is intended to be
used by the ss-core program, but it can be run directly for development and
debugging purposes.

See the "ss-hw" stuff in ss-core/PROTO for the protocol.  Remember, "ss-core"
is really whoever or whatever decides to execute ss-hw--- it only sees its own
stdin and stdout, which can easily be connected to your tty.  For all it cares
it could be running as an Internet service care of ucspi-tcp, netcat, or inetd!
