ANDROS: 10-10-2013 draft 05

Combined the Introduction/Motivation sections.

Removed client-identity assertions. Nico to justify and provide separate draft
for client-identity assertions.

As per Tom's request, removed Tom Haynes as an author.

Clarified how the GSS3 message encoding works. Noted that draft-05 did not:
1) address the rpc_gss_cred_vers_3_t seq_num stream, when it is to be a GSS3
   vrs parent context stream.
2) GSS3 Data messages absolutely need to use GSS3 context which was not stated
clearly.
3) Only GSS3_CREATE control message actually assigns the parent context to
the rpc_gss_cred_vers_3_t handle.

Replaced the 'string based' Privilege Assertion section with Structured
Privilege Assertions to clarify GSSv3 use for server-side copy. Note that
'string based' privilege assertions can be declared as a structured privilege.

Updated the label assertions to mirror NFSv4.2

Signed-off-by: Andy Adamson <andros@netapp.com>
ANDROS 10-16-2013 remove handle_version

The handle version is known:
The rpc_gss_cred_vers_3_t handle is a GSS3 handle for every case except for
RPCSEC_GSS3_CREATE where it is the parent (RPCSEC_GSSv1 or v2) handle.

Signed-off-by: Andy Adamson <andros@netapp.com>