Add PHP 5 compatible recursive dirname()

boot.php

@@ -854,3 +854,22 @@ function validate_include(&$file)
 	// Simply return flag
 	return $valid;
 }
+
+/**
+ * PHP 5 compatible dirname() with count parameter
+ *
+ * @see http://php.net/manual/en/function.dirname.php#113193
+ *
+ * @deprecated with PHP 7
+ * @param string $path
+ * @param int    $levels
+ * @return string
+ */
+function rdirname($path, $levels = 1)
+{
+	if ($levels > 1) {
+		return dirname(rdirname($path, --$levels));
+	} else {
+		return dirname($path);
+	}
+}