Switch to new php-encryption library version

- Remove references to library/ files
- Add namespace to library classes

include/items.php

@@ -33,9 +33,6 @@ require_once 'mod/share.php';
 require_once 'include/enotify.php';
 require_once 'include/group.php';
 
-/// @TODO one day with composer autoloader no more needed
-require_once 'library/defuse/php-encryption-1.2.1/Crypto.php';
-
 function construct_verb($item) {
 	if ($item['verb']) {
 		return $item['verb'];