[wayne s17] TuringMain copies .tur files from within jar to directory containing
            turing.jar (assuming they don't already exist). This is delicate,
            especially if turing.jar is located in an OS X app, so that copying would
            break the Gatekeeper security.

            Here's alternative code that might be more reliable

return new File(MyClass.class.getProtectionDomain().getCodeSource().getLocation().toURI().getPath());