update Piwik to version 2.16 (fixes #91)

www/analytics/plugins/MobileMessaging/ReportRenderer/ReportRendererException.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * Piwik - Open source web analytics
+ * Piwik - free/libre analytics platform
  *
  * @link http://piwik.org
  * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
@@ -68,4 +68,17 @@ class ReportRendererException extends ReportRenderer
     {
         // nothing to do
     }
+
+    /**
+     * Get report attachments, ex. graph images
+     *
+     * @param $report
+     * @param $processedReports
+     * @param $prettyDate
+     * @return array
+     */
+    public function getAttachments($report, $processedReports, $prettyDate)
+    {
+        return array();
+    }
 }