Before this data was serialized in order to fit a normal AVP and
be passed to DLGCB_CREATED callback. Moreover for transaction tracing
data was allocated in current process memory which would have crashed
if the reply were to be recieved in a different process. With the
current implementation data is allocated in shared memory, all processes
having access to it.
	For dialogs data is passed through xavp to dlgcb created. From
there all dialog callbacks are registered and they receive argument
the pointer to siptrace info. For transactions the pointer is passed
as dialog callback parameter.

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