An analogue S meter added

Do not blame me for the poor design. At least it tells you that the connection to the rig is alive.

DrawingArea::DrawingArea ()
{
  Glib::signal_timeout().connect( sigc::mem_fun(*this, &DrawingArea::on_timeout), 250 );
  #ifndef GLIBMM_DEFAULT_SIGNAL_HANDLERS_ENABLED
  //Connect the signal handler if it isn't already a virtual method override:
  signal_draw().connect(sigc::mem_fun(*this, &DrawingArea::on_draw), false);
  #endif //GLIBMM_DEFAULT_SIGNAL_HANDLERS_ENABLED
}

https://github.com/jh1ood/sprigmm/blob/develop/drawingarea.cpp