gpg: Auto-create revocation certificates.

* configure.ac (GNUPG_OPENPGP_REVOC_DIR): New config define.
* g10/revoke.c (create_revocation): Add arg "leadin".
(gen_standard_revoke): New.
* g10/openfile.c (get_openpgp_revocdir): New.
(open_outfile): Add MODE value 3.
* g10/keyid.c (hexfingerprint): New.
* g10/keygen.c (do_generate_keypair): Call gen_standard_revoke.
--

GnuPG-bug-id: 1042

tests/openpgp/Makefile.am

@@ -77,7 +77,7 @@ CLEANFILES = prepared.stamp x y yy z out err  $(data_files) \
 	     gnupg-test.stop pubring.gpg~ random_seed gpg-agent.log
 
 clean-local:
-	-rm -rf private-keys-v1.d
+	-rm -rf private-keys-v1.d openpgp-revocs.d
 
 
 # We need to depend on a couple of programs so that the tests don't