The locale management does not require sessions anymore.
In the Symfony2 spirit, the locale should be part of your URLs. If this is the case
(via the special _locale request attribute), Symfony will store it in the request
(getLocale()).
This feature is now also configurable/replaceable at will as everything is now managed
by the new LocaleListener event listener.
How to upgrade:
The default locale configuration has been moved from session to the main configuration:
Before:
framework:
session:
default_locale: en
After:
framework:
default_locale: en
Whenever you want to get the current locale, call getLocale() on the request (was on the
session before).