COMP: define a portable ExitEvent

Windows VS71 reports:
    iRen.AddObserver("ExitEvent", exit)
TypeError: a callable object is required

This patch provides a portable alternative

Change-Id: I2994530a458b776e4f9d6db6963536983044ce34
Merge topic 'PythonError_TestInteractorEventRecorder' into master

3060f8d7 COMP: define a portable ExitEvent