Commented out -setValue:forUndefinedKey: in NSObject+Prototypes since this causes failures in CoreObject test suite (temporary workaround until a solution is worked out)

git-svn-id: http://svn.gna.org/svn/etoile/trunk/Etoile/Frameworks/EtoileFoundation@10390 7b3f36aa-e6db-49c1-8b4c-66eac1997e64