Callback after entity is deleted. Note that you can not use `ossn_get_entity` within this hook as its already deleted. But you can use the guid to delete references in other places.

~~~
<?php
function my_component_init(){
ossn_register_callback('delete', 'entity', 'my_component_cb');
}
function my_component_cb($callback, $type, $params){
//$params['guid'] contains entity guid thats deleted already
}
ossn_register_callback('ossn', 'init', 'my_component_init');
~~~