+- Remove "save_state" option. Not maintained anymore; use clustering
+ to retain state across restarts.
+- Ensure that sessionkill is not called on an unopened session (borks
+ the freelist).
+- Bump MAXSESSION to 60K.
+- Fix off-by-one errors in session/tunnel initialisation and
+ sessiont <-> sessionidt functions.
+- Use session[s].opened consistently when checking for in-use sessions
+ (rather than session[s].tunnel).
+- Use <= cluster_highest_sessionid rather than < MAXSESSION in a
+ couple of loops.
+- Don't kill a whole tunnel if we're out of sessions.
+- Change session[s].ip to 0 if set from RADIUS to 255.255.255.254;
+ avoids the possibility that it will be interpreted as a valid IP
+ address.
+- Avoid a possible buffer overflow in processpap.
+- Kill session if authentication was rejected.