Enable an optional username:password to be provide on the command line to generate a Basic authentication header.
Enable an optional username:password to be provide on the command line to
generate a Basic authentication header.

* test/serf_get.c:
  (main): look for a third param, base64-encode it, and pass it in the
    "Authorization:" header.

jandre/serf,jandre/serf,jandre/serf,jandre/serf