Added generic signal binding for toolkit controls in JavaScript

Added generic signal binding for toolkit controls in JavaScript

This should cover generic use cases where the signal callback only needs to
be aware of who emits the signal and do not need to return any parameter.

This will work for most of control signals without specific binding.

For example, for button, you can do:

  var button = new dali.Control("PushButton");
  button.name = "myButton";
  button.connect("pressed", app.onButtonPressed);
  button.connect("released", app.onButtonReleased);

  app.onButtonPressed = function( button ) {
    console.log(button.name + " Pressed!!!");
  }

  app.onButtonReleased = function( button ) {
    console.log(button.name + " Released!!!");
  }

  button.disconnect("pressed", app.onButtonPressed);
  button.disconnect("released", app.onButtonReleased);

Change-Id: I3144ca274cc07e68d81ba78cc606e5367ea5419b