running the test case.

  that when we reap it and log a message.

  continue trying to read to see if an error message comes across
  explaining why the socket is closed.  I'm not sure if this would
  work, but it would certainly make our messages more helpful.

server.  This ought to exercise (exorcise? :-) a bug in 2.5.3.  It
ought to fail there and pass with later versions.

try to upload a file from rsync 2.5.2 to rsync 2.5.3

and don't try to call it if it doesn't exist.

the --no-blocking-io and --no-whole-file options.  This adds it back in.