Naming extensions implementation

[Luke Howard]

See:

	http://k5wiki.kerberos.org/wiki/Projects/VerifyAuthData

Note: this code is still a very rough implementation, it is not ready  
for review yet. The branch is users/lhoward/authdata.

However, today you can use it (see t_namingexts) to:

	* retrieve MS PAC buffers individually
	* determine whether the PAC was verified
	* plug in new authorization data verifiers/serializers
	* submit additional authorization data from initiator to acceptor

All public APIs are at the GSS layer and mirror draft-ietf-kitten- 
gssapi-naming-exts (with some slight changes).

cheers,

-- Luke	
--
www.padl.com | www.fghr.net