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/jplayer/skin/jplayer.audio-preview.blue.monday.css

@@ -89,12 +89,10 @@ div.jp-video div.jp-interface {
 }
 
 /* Used to hide the filename field **/
-span.filename {
-    display:none; 
-}
-span.name {
+span.fileID {
     display:none; 
 }
+
 /* @group CONTROLS */
 
 div.jp-controls-holder {