Add PGUSER to man page.

src/man/libpq.3

 .\" This is -*-nroff-*-
 .\" XXX standard disclaimer belongs here....
-.\" $Header: /cvsroot/pgsql/src/man/Attic/libpq.3,v 1.20 1998/07/14 02:41:26 momjian Exp $
+.\" $Header: /cvsroot/pgsql/src/man/Attic/libpq.3,v 1.21 1998/07/15 17:08:23 momjian Exp $
 .TH LIBPQ INTRO 07/08/98 PostgreSQL PostgreSQL
 .SH DESCRIPTION
 Libpq is the programmer's interface to Postgres.  Libpq is a set of
@@ -38,6 +38,10 @@ If it is set to a non-zero-length string, it causes TCP/IP
 communication to be used, rather than the default local Unix domain sockets.
 .sp
 \(bu
+.B PGUSER
+sets the username use to connect to the database and for authentication.
+.sp
+\(bu
 .B PGOPTIONS
 sets additional runtime options for the Postgres backend.
 .sp