re-added support for mp3, flac, etc

extras/wav2sketch/wav2sketch.html

@@ -18,7 +18,7 @@
         <option value="u-law">u-law</option>
         <option value="PCM">PCM</option>
       </select><br/><br/>
-      <input id="audioFileChooser" name="audioFileChooser" type="file" accept="audio/wav" multiple>
+      <input id="audioFileChooser" name="audioFileChooser" type="file" accept="audio/*" multiple>
       <div id="outputFileHolder"></div>
     </form>
     <script type="text/javascript" src="wav2sketch.js"></script>