Skin Editor - Toggle Buttons

Up and Down states:  art to display when the button is in its off and on states, respectively. Note that the ‘pushed’ states are created by buttons in the opposite state - i.e., when the button is in its down state and you click on it, it’ll switch to the up-state pushed art, and when the button is in its up state and you click on it, it’ll switch to the down-state pushed art.