fixed display bug in webkit because jquery draggable automatically adds
relative positioning to objects. Overrided this behaviour.
{{! template for the slider widget - it's composed of two divs we one overlayed on top
of the other }}
<div class='Ldt-sliderBackground'></div>
<div class='Ldt-sliderForeground'></div>
<div class='Ldt-sliderPositionMarker'></div>