pgsql: Support binary COPY through psql.

Log Message:
-----------
Support binary COPY through psql.  Also improve detection of write errors
during COPY OUT.  Andreas Pflug, some editorialization by moi.

Modified Files:
--------------
    pgsql/doc/src/sgml/ref:
        psql-ref.sgml (r1.161 -> r1.162)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/psql-ref.sgml.diff?r1=1.161&r2=1.162)
    pgsql/src/bin/psql:
        common.c (r1.117 -> r1.118)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/common.c.diff?r1=1.117&r2=1.118)
        copy.c (r1.60 -> r1.61)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/copy.c.diff?r1=1.60&r2=1.61)
        copy.h (r1.18 -> r1.19)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/copy.h.diff?r1=1.18&r2=1.19)