[Seaside] Hook for unregistering a handler

[Juergen Buchner]

Hello,

I would like to suggest to add a hook which is called when a handler is 
unregistered.

This can be done by changing the method 
WARegistry>>unregisterRequestHandler to:

unregisterRequestHandler: anObject
	anObject aboutToBeUnregistered.
	handlersByKey removeKey: (keysByHandler at: anObject).
	keysByHandler removeKey: anObject

and adding a method aboutToBeUnregistered

WARequestHandler>>aboutToBeUnregistered
	"nothing"

E.g. this hook can be used to perform any cleanup in a session.

Is it possible to add this hook in one of the next versions of Seaside?

Kind regards

Jürgen