Config and TT2 changes for surfacing CAS in TPAC

Config and TT2 changes for surfacing CAS in TPAC

These modifications:

1) assign the login and logout URLs for CAS support
2) replace the default cas_intro.tt2 screen with one specific to Windsor
3) show CAS_specific logout link if CAS is the authentication mechanism

Note that it is extremely important to have CAS logout with the
central CAS service since another user could have access to an account
on a public station. The central CAS service invalidates the ticket and
forces a new authentication session.

Signed-off-by: Art Rhyno <art632000@yahoo.ca>