Incorrect "References:" fields in news items

[Mark Plotnick]

Here are some fixes for the bogus References lines.

- In followup_command (and reply_command), change the code that
concatenates ", " to use " " instead.

- the code in hbufcp is kind of old, and doesn't copy the followid
field.  So, when a user does an f- command (the usual state of affairs),
there's no References line to be found in the followed-up-to article!
Hbufcp should really do a structure copy (except for the unrec
fields).

- the code in followup_command (and reply_command) blindly does lots of
strcats without looking to see whether it's overflowing folbuf.  If the
References line gets too long, folbuf won't be null-terminated, and the
string starting at folbuf will continue into the subj array (on a vax,
at least).  That's why you'll sometimes see "Subject:" near the end of
a References line.  The fix is to either have the code do strncats or
else just make folbuf[] immensely huge.

- the illegal Message-IDs are probably a result of the pre-2.10 news
systems that are still on the net.

	Mark Plotnick