(export_p12_file): Read a certificate from STDIN and pass it to
p12_build. Detect a keygrip and construct the filename in that
case. Unprotcet a key if needed. Print error messages for key
formats we can't handle.
(release_passphrase): New.
(get_passphrase): New arg PROMPTNO. Return the allocated
string. Changed all callers.
* minip12.c: Revamped the build part.
(p12_build): New args CERT and CERTLEN.
* simple-pwquery.c (agent_open): Don't mangle INFOSTR.
* export.c (export_p12, popen_protect_tool)
(gpgsm_p12_export): New.
* gpgsm.c (main): New command --export-secret-key-p12.
* findkey.c (agent_write_private_key,agent_key_from_file)
(agent_key_available): Use GNUPG_PRIVATE_KEYS_DIR constant.
* gpg-agent.c (main): Use GNUPG_DEFAULT_HOMEDIR constant.
* protect-tool.c (store_private_key): New.
(import_p12_file): Store the new file if requested.
(main): New options --force and --store.
* gpg-agent.c (main): Set a global flag when runing detached.
* query.c (start_pinentry): Pass the list of FD to keep in the
child when not running detached.
* call-scd.c (start_scd): Ditto.
