make SignedCookieListener work with RC5
make SignedCookieListener work with RC5

TODO:
* allow configuration on a per-domain basis
* tests for cookies with different domains

romainneutron/NelmioSecurityBundle,lyrixx/NelmioSecurityBundle,nelmio/NelmioSecurityBundle,stof/NelmioSecurityBundle,romainneutron/NelmioSecurityBundle