fixed 16:9 4:3 problems

templates/macros.html

@@ -56,7 +56,7 @@
 	<track srclang="de" kind="chapters" src="{{ url_for('chapters',lectureid=lecture.id) }}" />
 </video>
 <script>
-$('#videoplayer').addClass("vjs-16-9");
+$('#videoplayer').addClass("vjs-fluid");
 $('#videoplayer').css("width");
 $(function() {
 videojs("videoplayer").ready(function() {