Load history when a game is restored
I’ve defined the “saved-game” gsettings key to include the game history, so that its format does not require to be changed if someone closes this bug (yes, I could else have gone with variants in settings; but didn’t found it to be necessary, future will tell if I was right). But, so, this game history is currently not loaded, as I’d like to ensure, before loading it or at runtime –not sure–, that it doesn’t allow unauthorized moves. It would be great anyway to load it when restoring a game.