actually did not; fix it.

Add "make cleantests"

find a portable shell command that does it.

"nobody".  The existing code kind-of assumes this.

well as failing.

Doc.

Trying to work out why daemon-gzip-download.test fails on SCO with

  rsync error: unexplained error (code 190) at main.c(886)

user, so that we can cope on systems like Cygwin that tend to have
group names containing spaces.

      accepts a DESTDIR variable for help in building binary packages.
      (Peter Breitenlohner)

    * Fix situation where failure to fork (e.g. because out of process
      slots) would cause rsync to kill all processes owned by the
      current user.  Yes, really!  (Paul Haas, Martin Pool)

Also, add a little more documentation and paranoia to make sure we
never call kill(2) with a negative pid.

--whole-file and --no-whole-file options set/reset both variables so if
more than one option is specified the last one will be the one honored.

Add note about building with gcc.