* gssapiP_krb5.h (struct _krb5_gss_ctx_id_rec): Add a krb5 context object.

* gssapiP_krb5.h (struct _krb5_gss_ctx_id_rec): Add a krb5 context object.
* init_sec_context.c (krb5_gss_init_sec_context): Create a new krb5 context,
and store it in the security context if successful.  If there's already a
security context, use the krb5 context in it.
* accept_sec_context.c (krb5_gss_accept_sec_context): Create a new krb5
context, and store it in the security context if successful.
* delete_sec_context.c (krb5_gss_delete_sec_context): If the security context
has a krb5 context, free it.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@16170 dc483132-0cff-0310-8789-dd5450dbe970