- Windows will be first to use it, but in a future CL, with toolchain separate from Windows SDK
- Cleaned up some of the PlatformSDK API to have fewer public members (mainly so the functions that receive multiple versions can be automatically populated with the current single version functions in the subclasses)
- Updated the Turnkey menu to handle multiple versions
#jira none
#rb david.harvey
#preflight 62508cd8f10bcc0f4fa8b5d1
[CL 19692492 by Josh Adams in ue5-main branch]