pgbulkload - pgbulkload: Support a FILTER function without an argument.

Log Message:
-----------
Support a FILTER function without an argument.
Fix some problems.

Modified Files:
--------------
    pgbulkload/bin:
        pg_bulkload.c (r1.19 -> r1.20)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/bin/pg_bulkload.c?r1=1.19&r2=1.20)
    pgbulkload/include:
        reader.h (r1.14 -> r1.15)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/include/reader.h?r1=1.14&r2=1.15)
    pgbulkload/lib:
        parser_csv.c (r1.12 -> r1.13)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/parser_csv.c?r1=1.12&r2=1.13)
        parser_function.c (r1.6 -> r1.7)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/parser_function.c?r1=1.6&r2=1.7)
        pg_strutil.c (r1.9 -> r1.10)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/pg_strutil.c?r1=1.9&r2=1.10)
        reader.c (r1.17 -> r1.18)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbulkload/pgbulkload/lib/reader.c?r1=1.17&r2=1.18)