Windows NT 3.1 build 297

This build was the late June 1992 preliminary release for developers. KenOath first claimed to have this build, then it leaked on April 2011, along with the 10-91 and 10-92 pre-releases. This build can now properly shut down and introduces the safe to shutdown dialog that would be kept until early Windows NT 5.0 betas. Keyboard also now works for PCem.