1.1, if a view couldn't be restored due to session expiration, we'd create a new
one and go to render response.
In 1.2, this is not the case. We now throw a ViewExpiredException.
1.1-based applications may rely on the old behavior to forward to a login page
when a session expired. 1.2 circumvents this.
This should be listed as an incompatible change between 1.1 and 1.2 in the 1.2