TrackBase is a subclass of Range that provides thumb dragging functionality along a track. Slider and eventually ScrollBar will subclass TrackBase. Slider subclasses TrackBase and adds Slider-specific functionality like keyboard handling and track-click handling. HSlider and VSlider are initial implementations with tentative wireframe skins. Note: ScrollBar has not been changed to subclass TrackBase yet.
-Updated manifest/css files
-Added slider examples to flex4test