TODO: improveInstance Parameters===================Zope Parameters---------------Needed by software-type development (default) and zope.frontend-software-url~~~~~~~~~~~~~~~~~~~~~Software URL of an existing frontend.XXX: meaning should change (or it will go away) in order to be resilient tosoftware updates - as they are visible at software-url level.If it is not provided, no frontend will be requested.frontend-instance-guid~~~~~~~~~~~~~~~~~~~~~~GUID of frontend instance.Not perfect yet: if that instance is replaced, slaves have to be reconfigured.Mandatory only if frontend-software-url is also provided.XXX: should be complemented (or replaced) by more flexible and precisecriteria.frontend-software-type (optional)~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Frontend software type as defined by the software relase atfrontend-software-url.frontend-domain (optional)~~~~~~~~~~~~~~~~~~~~~~~~~~Domain name frontend must recognise as belonging to this instance.