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 (fe1bd4e8a88f42eded6fc4a99ad69f2ba90527d1) thing until we find a really elegant way (Bob proposed a good one).
XSLView contributed by Wes Hays