Adapt to imagecache2beta

In jlightbox_field_formatter_info() add ['presetname'] after $rulename in two places:

  foreach ($rules as $ruleid => $rulename) {
    $formatters['jlightbox]['. $rulename['presetname']] = array(
      'label' => 'jLightbox: '. $rulename['presetname'],
      'field types' => array('image'),
    );
  }

In jlightbox_field_formatter() change this section:

    if (in_array($namespace, (array)$rules)) {
      return theme('imagefield_jlightbox', $namespace, $formatter, $field, $item);
    }

to:

    foreach ($rules as $ruleid => $data) {
      if ($data['presetname'] == $namespace) {
        return theme('imagefield_jlightbox', $namespace, $formatter, $field, $item);
      }
    }

Marking as duplicate of #259471: Update for ImageCache 2 API. If something missed in the patch over there, please follow-up there.