systems (reported by Jay Fenlason).

a "struct file_list *", which allows us to call it with a copy of the
current file_struct entry that we've modified.  This is better than
modifying the entry directly because the latter causes the shared
memory between the generator and the receiver to slowly vanish as
the in-memory changes happen.

SunOS systems (and I hope the former works -- we'll see).

with the variables in the code that manipulates these values.

patch by Bardur Arantsson.

with autoconf 2.58 and above.

implements listening on multiple addresses and a fix for IPv6-only
systems.

non-root, and to ignore a gid of -1.

current file received some literal data yet or not.

f_name() returns.  Also used in a call to recv_generator() to keep the
name safe for the duration of the call.

This prevents things like the hard-link code from losing the name
before we're finished with it.

comparing two file_struct elements without copying them first, and
(2) f_name_to() which lets us supply the destination buffer for a
f_name() call (to allow it to persist without an extra copy).