picked this up -- quite neat.

isomorphic to sa_family etc from a struct sockaddr, not what they're
called.  On some platforms they seem not to be called ss_family.
Rather than guess, we will try casting to a sockaddr and looking
through that -- I think this is what the RFC intends.

sockaddr_storage is not defined, then supply our own definition that
will hopefully satisfy RFC2553 but also compile on all supported
platforms.

Thankyou to YOSHIFUJI Hideaki, SUMIKAWA Munechika and Jun-ichiro
"itojun" Hagino.

printed a second time when the modification time of the directory was
being set, and that time around recv_files() calls recv_generator() with
an f_out of -1 so check that before printing the directory name.

Based on a patch from Rik Faith, but modified to make sure we do only
one rprintf call, and that we never end up with two copies of the line
printed out.

attempting to free a static string.  (Thankyou to Paul Mackerras.)
There's still a small leak here.

Clean up test directory on completion.

number.