Expiration and V3/V4 self signatures

[Florian Weimer]

* packet.h, parse-packet.c (parse_key), getkey.c (merge_keys_and_selfsig,
merge_selfsigs_main): a v3 key with a v4 self-sig must never let the v4
self-sig express a key expiration time that extends beyond the original v3
expiration time.

* keyedit.c (sign_uids): If --expert it set, allow re-signing a uid to
promote a v3 self-sig to a v4 one.  This essentially deletes the old v3
self-sig and replaces it with a v4 one.

Don't these two features conflict with each other?

-- 
Florian Weimer 	                  Weimer at CERT.Uni-Stuttgart.DE
University of Stuttgart           http://CERT.Uni-Stuttgart.DE/people/fw/
RUS-CERT                          +49-711-685-5973/fax +49-711-685-5898