Add support for Spotify (squashed commit), and:

- Try to not return items which a client can't play
    - Remove inotify subscription to IN_MODIFY and IN_CREATE
    - Fix crash on unknown codec type in transcode.c
    - Probably added some new bugs...

src/httpd.c

@@ -395,8 +395,8 @@ httpd_stream_file(struct evhttp_request *req, int id)
 
       stream_cb = stream_chunk_xcode_cb;
 
-      st->xcode = transcode_setup(mfi, &st->size, 1);
-      if (!st->xcode)
+      ret = transcode_setup(&st->xcode, mfi, &st->size, 1);
+      if (ret < 0)
 	{
 	  DPRINTF(E_WARN, L_HTTPD, "Transcoding setup failed, aborting streaming\n");