scd: Silent compiler warnings about unused variables.

* scd/app-openpgp.c (build_ecdsa_privkey_template): Mark unused arg.
(ecdh_writekey): Mark unused args.

Signed-off-by: Werner Koch <wk@gnupg.org>
gpgconf: Add command --launch.

* tools/gpgconf.c: Add command --launch.
* tools/gpgconf-comp.c (gc_component_launch): New.

Signed-off-by: Werner Koch <wk@gnupg.org>
dirmngr: Fix compiler warning.

* common/mischelp.h (JNLIB_GCC_HAVE_PUSH_PRAGMA): New.
* dirmngr/dirmngr.c (handle_tick): Factor time check out to ...
(time_for_housekeeping_p): new.
--

I am not sure whether that y2038 hack is really useful but it might
make me smile in my retirement.
scd: EdDSA support.

* scd/app-openpgp.c (KEY_TYPE_EDDSA, CURVE_ED25519): New.
(struct app_local_s): Add eddsa.
(get_algo_byte, store_fpr): Support KEY_TYPE_EDDSA.
(get_ecc_key_parameters, get_curve_name): Support CURVE_ED25519.
(send_key_attr, get_public_key): Support KEY_TYPE_EDDSA.
(build_ecc_privkey_template): Rename as it supports both of
ECDSA and EdDSA.
(ecc_writekey): Rename.  Support CURVE_ED25519, too.
(do_writekey): Follow the change of ecc_writekey.
(do_auth): Support KEY_TYPE_EDDSA.
(parse_ecc_curve): Support CURVE_ED25519.  Bug fix for other curves.
(parse_algorithm_attribute): Bug fix for ECDH.  Support EdDSA.