Prior logic was using a common variable to encapsulate both these types and doing a runtime check based on GetTokenInformation call to determine the actual underlying type. These two types are not guaranteed to have different values and any conflict could result in a random crash that would be nearly impossible to debug.
Updated gss_release_cred() to test if passed structure is actually a logon token and, if so, release the data properly.
Addresses PowerShell/Win32-OpenSSH#1405
Added an implementation of GSSAPI interface to support Kerberos SSPI within OpenSSH. This is only a partial definition of the full GSSAPI specification since OpenSSH only requires a subset of the overall GSSAPI functionality.
