[HttpFoundation] added missing docs

Author: fabpot

src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php

@@ -92,6 +92,10 @@ class NativeSessionStorage implements SessionStorageInterface
      * upload_progress.freq, "1%"
      * upload_progress.min-freq, "1"
      * url_rewriter.tags, "a=href,area=href,frame=src,form=,fieldset="
+     * sid_length, "32"
+     * sid_bits_per_character, "5"
+     * trans_sid_hosts, $_SERVER['HTTP_HOST']
+     * trans_sid_tags, "a=href,area=href,frame=src,form="
      *
      * @param array                                                            $options Session configuration options
      * @param AbstractProxy|NativeSessionHandler|\SessionHandlerInterface|null $handler