made the listWidget redraw at every timeupdate event (added a small optimization though,
to make sure that the widget isn't redrawn all the time).
{{! template for an annotation displayed in a segmentWidget }}
<div title='{{divTitle}}' id='{{id}}'
class='Ldt-iri-chapter'
style='left: {{startPixel}}px;
width: {{pxWidth}}px;
background-color:#{{hexa_color}};'
>
</div>