Page callback: Presents the picture mapping editing form.
Drupal\picture\PictureMapping $picture_mapping:
A render array for a page containing a list of content.
function picture_mapping_page_edit($picture_mapping) {
drupal_set_title(t('<em>Edit picture mapping</em> @label', array(
'@label' => $picture_mapping
->label(),
)), PASS_THROUGH);
return entity_get_form($picture_mapping);
}