Having them declared statically in a header included by multiple compilation units results in duplicate functions being created.
Ensures that the UWP program can open the keepalive mutex to check to see whether OBS is still alive. Fixes a bug where UWP programs wouldn't capture.
The only way to open named kernel objects within a UWP "app" is to get the AppContainer SID, and then open the objects with their full system namespace names via undocumented NT functions.