fix de l'affichage de la playlist prompt lors de la lecture auto

src/Muzich/CoreBundle/Resources/public/css/main.css

@@ -2414,6 +2414,11 @@ form.playlist_edit input[type="submit"]
   margin-top: 5px;
 }
 
+div.playlists_prompt
+{
+  z-index: 99999;
+}
+
 /*
 *
 *

src/Muzich/CoreBundle/Resources/public/js/muzich.js

@@ -3191,7 +3191,7 @@ $(document).ready(function(){
     $(this).parents('div.playlists_prompt').find('img.loader').show();
   });
   
-  $('ul.elements a.add_to_playlist').live('click', function(event){
+  $('a.add_to_playlist').live('click', function(event){
     
     $('div.playlists_prompt').remove();
     var prompt = $('<div class="playlists_prompt nicebox"><img class="loader" src="/bundles/muzichcore/img/ajax-loader.gif" alt="loading..." /></div>');