Sound

Since I like it, I implemented sound. You need a sound board and a 
multi-media capable operating system, or you are restricted to beeps. 
If you switch sound on, you will get a sound

- when your opponent sets a stone, while you are investigating a
  variation.
- when you get a message, while you switched off the message dialogs.
- when you have sent a move to the server, which is not yet confirmed.

You can set the sounds to Simple getting less verbose sounds. If you set
it to Beeps, you get a beep, when it is your move and you cannot see
the move of your opponent, because you are in a variation, and you get a
beep, if you switched off messages and get a message.

I experience occasional hangs of the Java system, when sound is
enabled under Windows. This does not apply to beeps.

Moreover, you can turn on a warning counter, which will warn you, when
your time is getting low with 10 second ticks.
