If the global top only flag is on and a scene consumes an input event then they won't flow any further down the scene list. This is optional (but on by default), allowing you to now correctly create a UI Scene above a game scene without the input events polluting one to the other.
Graphics objects enabled for input would fail to do anything if a Phaser Polygon was given to the Graphics object (which it was in nearly all cases), as it wouldn't detect input correctly with flattened polygons (thanks @symbiane #2591)
Group.onChildInputUp is a new Signal that you can listen to. It will be dispatched whenever any immediate child of the Group emits an `onInputUp` signal itself. This allows you to listen for a Signal from the Group, rather than every Sprite within it.
Group.onChildInputOver is a new Signal that you can listen to. It will be dispatched whenever any immediate child of the Group emits an `onInputOver` signal itself. This allows you to listen for a Signal from the Group, rather than every Sprite within it.
Group.onChildInputOut is a new Signal that you can listen to. It will be dispatched whenever any immediate child of the Group emits an `onInputOut` signal itself. This allows you to listen for a Signal from the Group, rather than every Sprite within it.
The purpose of `processInteractiveObjects` is to work out which Game Object the Pointer is going to
interact with. It works by polling all of the valid game objects, and then slowly discounting those
that don't meet the criteria (i.e. they aren't under the Pointer, are disabled, invisible, etc).
Eventually a short-list of 'candidates' is created. These are all of the Game Objects which are valid
for input and overlap with the Pointer. If you need fine-grained control over which of the items is
selected then you can use this callback to do so.
The callback will be sent 3 parameters:
1) A reference to the Phaser.Pointer object that is processing the Items.
2) An array containing all potential interactive candidates. This is an array of `InputHandler` objects, not Sprites.
3) The current 'favorite' candidate, based on its priorityID and position in the display list.
Your callback MUST return one of the candidates sent to it.
Pointer.swapTarget allows you to change the `Pointer.targetObject` object to be the one provided. This allows you to have fine-grained control over which object the Pointer is targeting.
InputHandler._pointerOverHandler and _pointerOutHandler have new arguments `silent` - if `true` then they will not dispatch any Signals from the parent Sprite.
InputHandler.dragTimeThreshold gives you more fine control over when a Sprite Drag event will start. It allows you to specify a time, in ms that the pointer must have been held down for, before the drag will begin.
InputHandler.downPoint is a new Point object that contains the coordinates of the Pointer when it was first pressed down on the Sprite.
