Add "link" support

It would be great to allow <link> tags when adding customer header/footers so that we can include references to external stylesheets. To be able to do so in options-sanitize.php, I inserted a line after line 18:
$custom_allowedtags["link"] = array('href' => array(),'rel' => array(), 'type' => array());

But it would be great if I didn’t have to modify the theme’s code to have this functionality.

Great theme! Thanks!