* agent/command.c (cmd_genkey): Add option --passwd-nonce.
(cmd_passwd): Return a PASSWD_NONCE in verify mode.
* g10/call-agent.c (agent_genkey): Add arg 'passwd_nonce_addr' and do
not send a RESET if given.
(agent_passwd): Add arg 'verify'.
* g10/keygen.c (common_gen): Add optional arg 'passwd_nonce_addr'.
(gen_elg, gen_dsa, gen_ecc, gen_rsa, do_create): Ditto.
(generate_subkeypair): Use sepeare hexgrip var for the to be created
for hexgrip feature. Verify primary key first. Make use of the
passwd nonce. Allow for a static passphrase.
Signed-off-by: Werner Koch <wk@gnupg.org>