A SubState that Fades in and closes
Constructor
new (time:Float = 0.5, size:Int = 16, color:Int = 0xff000000)
Creates a new substate that fades in and closes
 *  @param time		the amount of time to fade in
 *  @param sprite	a sprite to show in place of a solid color
 *  @param color	a color to show in place of black