Balancing and small fixes update — Slipways Steam update #73407

Balancing changes to make the game more inviting on lowest difficulties: - the "Forgiving" difficulty is now quite a bit more "forgiving" when it comes to money and happiness - campaign mission have more difficulty scaling - they are slightly easier on "Reasonable" now, and much easier on "Forgiving" Other fixes: - Energy-driven Industry should no longer cause phantom products to remain after undo. - Keyboard scrolling should be more pleasant now. - You can now scroll the map using arrow keys if you prefer that/have a keyboard where WASD is uncomfortable - The version number is now displayed in the main menu in the bottom right corner.