* src/agent.c (pksign_parse_result): Support ECC signature in SEXP.
(scute_agent_sign): Support ECC signing.
* src/cert-object.c (asn1_get_ec_params): New.
(scute_attr_prv): Support ECC mechanism.
* src/p11-signinit.c (C_SignInit): Remove the check for RSA.
* src/slots.c (struct slot): Add key_type.
(mechanism_alloc): Get the mechanism from the certificate.
(slot_alloc): Don't allocate mechanisms here.
(slot_init): Allocate mechanisms here.
(session_sign): Support returning the length of signature
for ECC.