BT, EMBEDDED, thread joining

Fix a few BT issues (detection & sink name)
End threads on any server missing for too long (except if server IP set
manually)
Still cannot end threads when BT active (works wit I2S)
Thread lokc-up still happens when switching tracks quickly

components/squeezelite/output_i2s.c

@@ -167,6 +167,11 @@ void output_init_i2s(log_level level, char *device, unsigned output_buf_size, ch
  * Terminate DAC output
  */
 void output_close_i2s(void) {
+	LOCK;
+	running = false;
+	UNLOCK;
+	pthread_join(thread, NULL);
+	pthread_join(stats_thread, NULL);
 	i2s_driver_uninstall(CONFIG_I2S_NUM);
 	free(obuf);
 }