gss_acquire_cred with GSS_C_BOTH usage option

[Sam Hartman]

I see your point and I agree the Heimdal behavior is useful in the
case you describe.

However it seems to violate the principle of least surprise.  If I
change my application to start requesting initiator credentials
instead of both credentials then initiator credentials can stop
working if I don't have a current cache.

I'm not sure how to resolve these requirements.

--Sam