Saves NVR on exit, fatal, and before any kind of menu or configuration change triggered reset, rather than every second. Should improve performance and reduce disk writes.

src/pc.c

@@ -91,6 +91,7 @@ void fatal(const char *format, ...)
    vprintf(format, ap);
    va_end(ap);
    fflush(stdout);
+   savenvr();
    dumppic();
    dumpregs();
    fflush(stdout);