Optimize YR and fix bug!!

[AlexB]

Ares does fix a lot of bugs already, but that isn't the only purpose of Ares. Personally, I don't see the need to spend my time to only fix bugs in Yuri's Revenge and to optimize it. But I would not refuse to include any working bugfix another coder came up with. That is, a change not for the sake of change, but a fix for a game behavior that is widely considered a bug.