v1.23

Hi everyone.

Here is the release note:

FIXED:
- Missing Offshore Platform 3D Object
- Always at war option (you cannot contact anymore a civilization when this option is enabled)
- Tutorial crash
- Improve action (does not anymore propose you wrong improvements, like roads on water)

UPDATED:
- Cannot anymore "Air Transport" naval units
- Hydro Plant requires now a river (before it required ocean)

NEW:
- Can close City Menu by clicking the city's button a second time

Bruno