- Add @ to swapkey, to disable it in classification

- Modify key Compromise for protocols that contain a timestamp to make the
  key compromise disclose a timestamp with a different type, namely 
  ExpiredTimeStamp so that they will not be accepted as timestamps in a new
  session, thereby simulating that they are expired.

spdl/SPORE/andrew-ban-concrete.spdl

@@ -21,7 +21,7 @@ secret k: Function;
 const Fresh: Function;
 const Compromised: Function;
 
-protocol swapkey(X)
+protocol @swapkey(X)
 {
     # Protocol added to work around the symmetry problems where k(I,R) != k(R,I)
     role X