Freeciv

Currently "Save" button in the client options dialog does not necessarily save values that are visible in the dialog. It saves the values that user has clicked "Apply" for. It does not do the 'apply' automatically.

The challenge with automatic apply + save has been that the apply sends server settings to a round trip to the server, and they can be saved only once we've received them back from the server. To resolve that, PACKET_SYNC_SERIAL and PACKET_SYNC_SERIAL_REPLY have already been introduced to freeciv-3.2 and later. Now we only need to add the logic to postpone actual options saving until server has replied.