Attached are diffs (from current cvs sources) to bring libpq.sgml
and libpq.3 up to date.

It appears that at various times in the past, people have made edits to
one or the other of these files but not both.  I propagated some changes
from each into the other, but I don't think I caught every
inconsistency.  It'd be real nice if the man pages could be
automatically generated from the SGML...