jQuery.each causes scripts to bomb if there are no settings

I'm using jCarousel with callback functions, whose names cannot be passed through drupal_to_js. When I just call jq_add('jcarousel') or jcarousel_add(), the browser javascript bombs with an error and all other scripts on the page never run. This is because you're attempting to run jQuery.each() on a non-existent array.

Here's a patch that gets me through this spot.