Adds support for links -> HTML5 audio elements

Turns links to web-published .mp3, .ogg, and .wav files into HTML5
audio elements

src/sidebar/media-embedder.js

@@ -4,12 +4,11 @@
 * Return an HTML5 audio player with the given src URL.
 */
 
-function mp3audio(src) {
+function audioElement(src) {
   var html5audio = document.createElement('audio');
   html5audio.id       = 'audio-player';
   html5audio.controls = 'controls';
   html5audio.src      =  src;
-   html5audio.type     = 'audio/mpeg';
   return html5audio;
 }
 
@@ -102,10 +101,10 @@ var embedGenerators = [
     return null;
   },
 
-  // Matches URLs that have .mp3 in them (assumed to be audio files)
+  // Matches URLs that end with .mp3, .ogg, or .wav (assumed to be audio files)
   function html5audioFromMp3Link(link) {
-	if (link.href.toLowerCase().indexOf('.mp3') !== -1) {
-	  return mp3audio(link.href);
+    if (link.pathname.endsWith('.mp3') || link.pathname.endsWith('.ogg') || link.pathname.endsWith('.wav')) {
+      return audioElement(link.href);
     }
     return null;
   },