- Refactors sending queue worker by breaking it into smaller tasks

- Adds arrayUnique method to Helpers for multidimensional arrays

lib/Util/Helpers.php

@@ -2,6 +2,8 @@
 namespace MailPoet\Util;
 
 class Helpers {
+  const DIVIDER = '***MailPoet***';
+
   static function getMaxPostSize($bytes = false) {
     $maxPostSize = ini_get('post_max_size');
     if(!$bytes) return $maxPostSize;
@@ -122,4 +124,12 @@ class Helpers {
       )
     );
   }
+
+  static function joinObject($object = array()) {
+    return implode(self::DIVIDER, $object);
+  }
+
+  static function splitObject($object = array()) {
+    return explode(self::DIVIDER, $object);
+  }
 }