Use hidden divs, not Drupal.settings, to pass thumbnail data to Javascript

Currently we use Drupal.settings to pass the thumbnail version of the field forward to jQuery. That works fine, unless you do ajax paging in which case you are missing data. Right now we're doing some horrific crap in the preprocess function to pass forward extra bits of Drupal.settings. Instead, let's just use hidden divs and match based on their ID instead. Much cleaner.