Allow CAS to return ticket objects rather than mere identifers

Various operations in our service layer, namely CAS, tend to return identifiers for tickets that are created or delegated rather than the actual object. This sort of encourages/forces downstream components to require access to ticket registry (like AuthenticationViaFormAction) so they could peek into the TGT or ST object. 

What's implemented here is the reverse; CAS now returns types of TicketGrantingTicket and ServiceTicket back to callers. This removes the need access to the registry, and of course makes the code more efficient as ops to registry would be reduced. 

Also deprecated the RemoteCAS impl.