Trace should should provide the ability to autoflush harness.trace

com.sun.javatest.Trace reads the system property `javatest.trace.autoflush` but ignores the result.
It would be nice if the setting could be honored and/or if the default was changed to autoflush:true

    private void openOutput(Parameters params) {
        try {
            WorkDirectory wd = params.getWorkDirectory();
            File traceFile = wd.getSystemFile("harness.trace");
            boolean autoFlush = Boolean.getBoolean("javatest.trace.autoflush"); //<<<<<<<<*********
            out = new TextWriter(backupPolicy.backupAndOpenWriter(traceFile));
            // The following output is verified.
            out.println("# Trace file started at " + (new Date()));
            out.println("# " + ProductInfo.getName() + " version " + ProductInfo.getVersion());
            out.println("# class directory: " + Harness.getClassDir());
            out.println("# using java: " + System.getProperty("java.home"));
        }
        catch (IOException e) {
            System.err.println("Cannot open trace file: trace cancelled");
            System.err.println(e);
            out = null;
        }
    }