- The code starting a tutorial race was duplicated in three places. Consolidate it in one place.
- When launching the tutorial from the overworld, use the last used input device instead of the keyboard
- Restore the old cmake policy. The new way to replace that code suggested by the cmake manual fails CI, and debugging MSVC fantasies without a local install is a nightmare.
- Restrict this policy setting to MSVC as that's the only compile path that needs it, avoiding the warning for non-MSVC builds.
- Add missing define guards
- Remove some extraneous includes
