
FIXED:
BUG2 :          06022002   0.8.1
  With the new fsm, some messages must be handled without giving
  them to the state machines. This is the case when receiving more
  than one 2xx responses. In the case where a 2xx has been received,
  the rfc says that it's up to the "transaction user" to deal with
  the message without the use of the transaction layer. This is needed
  because behavior is different in this case for UA and proxy. (and the
  state machines are usable by both UA and proxy since 0.8.1!)

  By now, instead of refusing the 2xx messages, and leave it to the
  "transaction user" layer, the fsm will discard the event without
  telling the upper layer. This behavior will be fixed to leave
  the choice of deleting the message up to the user.

  An other important modification in the latest draft of SIP (which
  has result in a modification of the fsm library) is the handling of
  ACK. For any response superior to 299, the ACK is completely
  handled by the fsm. You don't have to build it and send it as it's
  automated. (both proxy and UA handles those ACK following the same
  procedures in the latest draft of SIP! That's why...). Nevertheless,
  you'll have handle 2XX (for INVITE) in the "transaction user" alone:
  Proxy will forward the 2xx and UA will sends special ACK within the
  dialog.


