pgsql: Remove advertising clause from Berkeley BSD-licensed files, per

Log Message:
-----------
Remove advertising clause from Berkeley BSD-licensed files, per
instructions from Berkeley.

Modified Files:
--------------
    pgsql/src/backend/port/darwin:
        system.c (r1.5 -> r1.6)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/port/darwin/system.c.diff?r1=1.5&r2=1.6)
    pgsql/src/backend/port/dynloader:
        freebsd.c (r1.26 -> r1.27)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/port/dynloader/freebsd.c.diff?r1=1.26&r2=1.27)
        netbsd.c (r1.20 -> r1.21)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/port/dynloader/netbsd.c.diff?r1=1.20&r2=1.21)
        openbsd.c (r1.20 -> r1.21)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/port/dynloader/openbsd.c.diff?r1=1.20&r2=1.21)
    pgsql/src/backend/utils/mb:
        wstrcmp.c (r1.7 -> r1.8)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/wstrcmp.c.diff?r1=1.7&r2=1.8)
        wstrncmp.c (r1.7 -> r1.8)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/wstrncmp.c.diff?r1=1.7&r2=1.8)
    pgsql/src/port:
        getopt.c (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/getopt.c.diff?r1=1.10&r2=1.11)
        getopt_long.c (r1.5 -> r1.6)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/getopt_long.c.diff?r1=1.5&r2=1.6)
        inet_aton.c (r1.9 -> r1.10)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/inet_aton.c.diff?r1=1.9&r2=1.10)
        snprintf.c (r1.33 -> r1.34)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/snprintf.c.diff?r1=1.33&r2=1.34)
        strtol.c (r1.12 -> r1.13)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/strtol.c.diff?r1=1.12&r2=1.13)
        strtoul.c (r1.2 -> r1.3)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/strtoul.c.diff?r1=1.2&r2=1.3)