Stop recording when final game state was reached

[kompot]

So that it would be possible to use this for automatic recording.

[rseanhall]

This would be hard to implement correctly. The program would need to know the current time in the recording. That might not be the current time for the local machine, because the recording might have started late in the game and it hasn't caught up to real time yet. Today, the recording does eventually stop when the stream ends (or there was a connection issue, which is another issue that would need to be solved for automated usage).