CC-3391: Audio Preview cannot play tracks with commas in their filename

- The content distribution header filename attribute, wasn't properly quoted for inline content. This causes a bug for files with comma names.
- changed the play button in library back to the speaker icon
- removed some dead code preview_player.js
- removed the file name attribute, will need better approch to presenting the user with audio information.

airtime_mvc/public/js/airtime/library/spl.js

@@ -248,11 +248,10 @@ var AIRTIME = (function(AIRTIME){
     function openAudioPreview(event) {
         event.stopPropagation();
         
-        var name = $(this).parent().find('.spl_title').text();
         var audioFile = $(this).attr('audioFile');
         var id = "";
         
-        open_audio_preview(name, audioFile, id);
+        open_audio_preview(audioFile, id);
     }      
     
 	function editName() {