get_in_tkt.c (krb5_get_in_tkt): If kdc_settime is enabled, then set

get_in_tkt.c (krb5_get_in_tkt): If kdc_settime is enabled, then set
	the time_offset fields from the returned ticket's authtime value.

init_ctx.c (krb5_init_context): Initialize new fields in krb5_context
	(clockskew, kdc_req_sumtype, and kdc_default_options).

gc_via_tkt.c (krb5_get_cred_via_tkt): Perform the necessary
	sanity checking on the KDC response to make sure we detect tampering.

send_tgs.c (krb5_send_tgs): Set the expected nonce in the response
	structure.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@6653 dc483132-0cff-0310-8789-dd5450dbe970