Loads system variables and all enabled bootstrap modules.
function _drupal_bootstrap_variables() {
global $conf;
// Load variables from the database, but do not overwrite variables set in settings.php.
$conf = variable_initialize(isset($conf) ? $conf : array());
// Load bootstrap modules.
require_once DRUPAL_ROOT . '/core/includes/module.inc';
module_load_all(TRUE);
}