Revisiting krb5_gic_opt_ext

[Greg Hudson]

On Wed, 2009-11-25 at 15:58 -0500, Jeffrey Hutzelman wrote:
> 4. Make opt_to_opte copy the structure only when the input is non-extended, 
> and add a refcount to the extended version of the structure.  Creating an 
> alias increments the refcount, and callers that currently free when the 
> "shadowed" flag is set should instead call a put operation that decs the 
> refcount and frees when appropriate.

I might do this as the stopgap for merging Luke's code.  The options I
listed involve either copying an extended options structure (kind of a
pain in the butt due to the complexity of the preauth_data field) or
creating merge hassles for Sam and Luke by touching a bunch of code in
the AS path.

There are only three places where we call opt_to_opte with the force
flag set, so converting the corresponding frees should be fairly
painless.

I'll amend #6034 to note the possiblity of eliminating the copies to
simplify memory management, and that will be a future cleanup task.