Version almost final

lecture: Almost perfect caching with FOSHttpCache


At eZ we have been lucky to work with so many talented developers in the PHP and Symfony community, and one of the projects we have so far have contributed to in ideas and code and also benefitted from is FOSHttpCache, a super charged Http Cache implementation with tagging of content, varying of cache by user cache, support for Varnish, Symfony Proxy and Nginx, and much more. But it can still be improved, multi tagging support for Symfony Proxy, and Stale cache handling on purges by tags are two currently missing features for handling all possible high load situations.