using jquery ui draggable changes the state of an element from absolute to relative
positioning, which breaks the way our seek button expands itself, so we need to
force absolute positioning, quite uglily, using jquery.
{{! 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>