It would be useful to put a getSharedInstance() method in ERXSystem and
a system() method in ERXApplication that returns the ERXSystem shared
instance. Then I could use bindings like application.system.myProperty
to access system properties. It looks like that was the intention of
having ERXSystem with key-value coding, but maybe there is some reason
why david decided not to implement a getInstance method ...... or is
there another class that I have not found in PW that gets properties
via key-value coding?