URLs truncated on Image widgets

The ability to link an Image widget was introduced in Panopoly 1.38 (see #2013965: ability to link images placed with image widget). There's been a bug in this since introduction. When you have a URL that ends up being longer than 80 characters, the href attribute of the a tag that's generated when the widget is rendered is truncated to 80 characters plus an ellipsis.

To reproduce:

1. Do a clean install of Panopoly 1.41 with demo content.
2. Log in as the administrator.
3. Create a Content Page with an extremely long permalink.
4. On the home page, click Customize this page.
5. Click the Add button for a region.
6. Click Add image.
7. Click Browse and select an image from the library.
8. Click the Search for existing content button for the Link field.
9. Search for and select the page you created with the long permalink.
10. Click Insert link.
11. Note the link is inserted in the form node/NID.
12. Click Save in the add content modal.
13. Click Save at the bottom of the page.
14. Hover over the linked image.
15. Note the URL is truncated and ends with an ellipsis.
16. Click the image to follow the link.
17. Note you see a Page Not Found error.

This is probably because the display_url is being output instead of the url:

/**
 * Implements hook_fieldable_panels_pane_view().
 */
function panopoly_widgets_fieldable_panels_pane_view($entity, $view_mode, $langcode) {
  if ($entity->bundle == 'image') {
    // Render the image in a link if one is given.
    if (!empty($entity->field_basic_image_link[LANGUAGE_NONE][0]['url'])) {
      $entity->content['field_basic_image_image'][0]['#path'] = array(
        'path' => $entity->field_basic_image_link[LANGUAGE_NONE][0]['display_url'],
      );
    }
  }
}