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.
/*
*
* Copyright 2010 Institut de recherche et d'innovation
* contributor(s) : Samuel Huron
*
* contact@iri.centrepompidou.fr
* http://www.iri.centrepompidou.fr
*
* This software is a computer program whose purpose is to show and add annotations on a video .
* This software is governed by the CeCILL-C license under French law and
* abiding by the rules of distribution of free software. You can use,
* modify and/ or redistribute the software under the terms of the CeCILL-C
* license as circulated by CEA, CNRS and INRIA at the following URL
* "http://www.cecill.info".
*
* The fact that you are presently reading this means that you have had
* knowledge of the CeCILL-C license and that you accept its terms.
*/