Release 12 of the FreeOrionSDK
v12 - 2021-04-25
- Update boost version to 1.74
- Update Python3 version to 3.6.5
- Update SDL2 version to 2.0.12
- Update lippng version to 1.6.37
- Update GLEW version to 2.2.0
- Bump C++ standard to C++17
- Raise Mac OS X build environment to Xcode 10.1
- Removed separate specification of Mac OS X deployment target version