DataSealer dependencies

[Cantor, Scott]

> There is no "CAS session" per se; the CAS session is the IdP session. The IdP
> session does the session tracking, the CAS protocol simply looks up the IdP
> session and stores the service information (if the session is found). This is the
> functionality that you'd lose with dropping server-side storage: no SLO for
> CAS services.

If the logout is front-channel, you wouldn't lose that.

-- Scott