* Added tiling and scaling and opaque to Icon.
 * Changed the inheritance of CheckBox and RadioButton.CheckBox inherits from ImageButton and RadioButton inherits from CheckBox.
 * Added more marker possibilities.
 * Added a optional background image for CheckBox and RadioButton, the size should be large enough to include the caption.
 * Added ToggleButton. It inherits from ImageButton but have additional the possibility for a group like RadioButton.