pgsql: Provide for logfiles in machine readable CSV format.

Log Message:
-----------
Provide for logfiles in machine readable CSV format. In consequence, rename
redirect_stderr to logging_collector.
Original patch from Arul Shaji, subsequently modified by Greg Smith, and then
heavily modified by me.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        config.sgml (r1.137 -> r1.138)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/config.sgml?r1=1.137&r2=1.138)
        func.sgml (r1.385 -> r1.386)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml?r1=1.385&r2=1.386)
        maintenance.sgml (r1.77 -> r1.78)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/maintenance.sgml?r1=1.77&r2=1.78)
    pgsql/src/backend/postmaster:
        postmaster.c (r1.540 -> r1.541)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/postmaster/postmaster.c?r1=1.540&r2=1.541)
        syslogger.c (r1.36 -> r1.37)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/postmaster/syslogger.c?r1=1.36&r2=1.37)
    pgsql/src/backend/utils/adt:
        misc.c (r1.56 -> r1.57)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/misc.c?r1=1.56&r2=1.57)
    pgsql/src/backend/utils/error:
        elog.c (r1.193 -> r1.194)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/error/elog.c?r1=1.193&r2=1.194)
    pgsql/src/backend/utils/misc:
        guc.c (r1.412 -> r1.413)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c?r1=1.412&r2=1.413)
        postgresql.conf.sample (r1.223 -> r1.224)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/postgresql.conf.sample?r1=1.223&r2=1.224)
    pgsql/src/include/postmaster:
        syslogger.h (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/postmaster/syslogger.h?r1=1.10&r2=1.11)
    pgsql/src/include/utils:
        elog.h (r1.87 -> r1.88)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/elog.h?r1=1.87&r2=1.88)
    pgsql/src/test/bench:
        runwisc.sh (r1.9 -> r1.10)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/bench/runwisc.sh?r1=1.9&r2=1.10)