Implemented timerange for mdplayer and use of it in widget Segment: if enable (option is use_timerange) when clicking a segment user can only read the video on current segment + adapted other widgets that need to detect segment to be able to use this option if it is enable so that segment detection is smoother + adjusted API testing form on iframetesting to use the correct api (form is still hidden by default)

// Opacity

.opacity(@opacity) {
  opacity: @opacity;
  // IE8 filter
  @opacity-ie: (@opacity * 100);
  filter: ~"alpha(opacity=@{opacity-ie})";
}