Merge remote-tracking branch 'origin/unicode_password' into merge_branch

Workaround for PTY regressions

Changes from PowerShell#353 enabled closing of previously duplicated Console handles - this is causing TTY rendering issues in ssh.exe.
Added a workaround for now to skip closing Console handles.

Workaround for PTY regressions

Changes from PowerShell#353 enabled closing of previously duplicated Console handles - this is causing TTY rendering issues in ssh.exe.
Added a workaround for now to skip closing Console handles.

Add Zlib Library For Compression Support

- Added an empty project with a script to dynamically download zlib source and compile it into a static library.
- Updated other projects to link with new zlib library.
- Removed zlib preprocessor workarounds and function stubs now that real library is in place.

Provide Kerberos SSPI Support Via GSSAPI - Revisions

- Corrected FreeContextBuffer() target pointer.

OpenSSH for Windows 7.6.0.0

Enabled Control Flow Guard on all projects