uGUI: Reverted the default behavior for UI elements that implement IPointerEnter/Exit back to what it was before: when hovering a child component, it also sends the hovering event to the parent(s).
Also added a field (sendPointerHoverToParent) in the BaseInputModule that can be set to false to change the behavior to: when hovering a child component, it doesn't send the hover event to the parent(s).