PHP 5.1.0 compatibility fix for PDODatabase
Support for username and password in PDODatabase. Needed for MySQL and others. Also added PDO "documentation" in databases.ini
Made all AG_* configuration directives except AG_WEBAPP_DIR optional and backed out that AG_CHECK_CONFIGS (f193febaedac62c670eea5e1008216da3c75ddee) thing until we find a really elegant way (Bob proposed a good one).
XSLView contributed by Wes Hays