Added updateDisplay on GUI object

[Ucodia]

Currently manual update was only available on individual controllers and folders.

// update controllers
for (var c in gui.__controllers) {
  gui.__controllers[c].updateDisplay();
}

// update folders controllers
for (var f in gui.__folders) {
  for (var fc in gui.__folders[f].__controllers) {
    gui.__folders[f].__controllers[fc].updateDisplay(); 
  }
}

This commit adds an updateDisplay() method on the GUI object that recurses on all its controllers and folders to request a grahical update. Thus refreshing the whole UI becomes more straightforward, especially with folders.

gui.updateDisplay();

[customlogic]

Thanks! I've slightly modified and merged your code into develop 0399ab6