Add fivestar_compute_average(), fivestar_container_id(), _fivestar_field_formatter_view_pageshow(), fivestar_retrieve() and theme_fivestar_average(). Change fivestar_compute_value() to fivestar_compute_rating(). Change fivestar_field_formatter_view() to place an empty div container for fivestar fields that are set as parent targets on other fivestar fields, and setup a pageshow to inject the rating into the container. Change theme_fivestar() to handle better handle variables.