* g10/gpg.c (cmd_and_opt_values): Add delete-secret-key-stubs command.
(opts): Add delete-secret-key-stubs argparse option.
(main): Parse and invoke the delete-secret-key-stubs command.
* g10/main.h (delete_keys): Add the stubs_only parameter.
* g10/delkey.c (delete_keys): Likewise.
(do_delete_key): Likewise.
(gpg_agent_delete_secret_key): Likewise.
* g10/call-agent.h (agent_delete_key): Likewise.
* g10/call-agent.c (agent_delete_key): Pass --stub-only to gpg agent.
--
The new --delete-secret-key-stubs command provides access to
the --stub-only option of the gpg agent's DELETE_KEY command.
Signed-off-by: Matheus Afonso Martins Moreira <matheus.a.m.moreira@gmail.com>