FEATURE: Updated SiteTree::get_by_link() to integrate with translatable, and allow it to work across languages by implementing Translatable->alternateGetByLink().
API CHANGE: Moved lang_filter enabling & disabling into static methods on Translatable, and renamed to locale_filter.
BUGFIX: Fixed viewing a translatable page by URL without explicitly setting a Locale in ContentController->handleRequest().
From: Andrew Short <andrewjshort@gmail.com>
git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@88503 467b73ca-7a2a-4603-9d3b-597d59a354a9