beam/data: expose EncodeString for convenience access to the underlying netstring primitive
beam/examples/beamsh: more useful debugging
beam/examples/beamsh: don't print discarded messages in Devnull, to avoid false alarms when process exits without printing. Devnull doesn't require synchronization
beam/examples/beamsh: 'exec' command correctly closes stdout and stderr when the process exists
beam/examples/beamsh: 'beamsend' command serializes all messages and sends them over a network connection