Make mechanism interfaces that are optional in usage, optional in
implementation, i.e. do not require them to be present when dynamically loading
a mechanism. In order to aid minimal mechanism implementation, more of these
should likely be made optional (this will require an additional check in the
mechglue to return GSS_S_UNAVAILABLE if the function pointer is NULL). This is
left as a future exercise.
Luke Howard
64d5d138a9