Strict routes based on allowed locales

Hi!
This patch allows to stop the request when a non-allowed locale is requested.

Is useful if your paths looks like `/en_GB/content`,and you don't want to have `/en_US/content`.
(without this patch, when `strict_mode=false`, the "country" part of locale is never tested, so urls like  `/en_XXXXXXXXXXXX/content` always exists).