Updated LatestAnnotation, CurrentSegmentInfobox, AnnotationController and AnnotationList widgets to use timerange to find the current segment when the corresponding option is used + CurrentSegmentInfobox now has an option for editing the current segment + LatestAnnotation now has a "Copy and edit" button that allows to use the text from the currently displayed annotation into the CreateAnnotation widget textarea
Altered ldt_annotate serializer to allow for serializing id for editing annotation + Added Markers widget that allows to make and edit 0 duration annotations.
Added support for defining a "time range" for a Playable to set the time boundaries of what can be played by the diffenrent players (Popcorn and HtmlPlayer for now). Added option in Segment widget to define a timerange on click.