[krbdev.mit.edu #5445] gsstest doesn't like krb5-1.6 GSSAPI library

[Ken Raeburn via RT]

The gsstest program seems to assume that the pre-rfc1964 OID for krb5 will be chosen as the 
default by the loaded library, not the rfc1964 OID.  With a tweak to the program to reverse that, 
and the patches checked in so far, gsstest seems happy now except for the two problems 
relating to acquiring default acceptor credentials.

The problem seems to be that the mechglue code saves away a null pointer and zero length for 
the name for the default credentials, and when inquired for the name, tries to import that 
invalid name string internally, and reports an error.  So acquire_creds works and returns a 
credential handle, but inquire_cred calls it invalid.