The HttpFoundation Component defines an object-oriented layer for the HTTP
specification.
In PHP, the request is represented by some global variables ($_GET, $_POST,
$_FILES, $_COOKIE, $_SESSION, ...) and the response is generated by some
functions (echo, header, setcookie, ...).
The Symfony HttpFoundation component replaces these default PHP global
variables and functions by an Object-Oriented layer.
Optional:
* Memcache (php-pecl-memcache)
* Memcached (php-pecl-memcached)
* Mongo (php-pecl-mongo)
