#105 Update CUBRID PDO driver manual

[Jira Trac]

Please update [PDO_CUBRID DSN|http://www.php.net/manual/en/ref.pdo-cubrid.connection.php] manual page to instruct users to pass *username* and *password* to PDO. The issue has been reported in the [forum|http://www.cubrid.org/?mid=forumdocument_srl=304563rnd=306836#comment_305695].