$gallery->session->configData .= "/* Features */\n";
foreach ($features as $feature => $dependents) {
        $use = 1;
        $cause = "";
        foreach ($dependents as $dep) {
                if (!isset($$dep) && !isset($gallery->session->configForm->$dep)) {
                        $use = 0;
                        if ($cause) {
                                $cause .= ", ";
                        }
                        $cause .= _("missing") ." <i>$dep</i> -- " . _("it's optional");
                }
        }

        if ($use) {
                $gallery->session->configData .= use_feature($feature);
        } else {
                $gallery->session->configData .= no_feature($feature, $cause);
        }
}