pgbulkload - pgbulkload: Report conflicted values for duplicate keys.

Log Message:
-----------
Report conflicted values for duplicate keys.
(ported from report_dupkey patch for 8.5)

Modified Files:
--------------
    pgbulkload/include:
        pg_bulkload.h (r1.4 -> r1.5)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/include/pg_bulkload.h.diff?r1=1.4&r2=1.5)
    pgbulkload/lib:
        pg_btree.c (r1.3 -> r1.4)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/pg_btree.c.diff?r1=1.3&r2=1.4)
        pg_bulkload.c (r1.4 -> r1.5)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/pg_bulkload.c.diff?r1=1.4&r2=1.5)
        pg_controlinfo.c (r1.4 -> r1.5)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/pg_controlinfo.c.diff?r1=1.4&r2=1.5)
        pg_heap_buffered.c (r1.4 -> r1.5)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/pg_heap_buffered.c.diff?r1=1.4&r2=1.5)
        pg_heap_direct.c (r1.4 -> r1.5)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/pg_heap_direct.c.diff?r1=1.4&r2=1.5)