tools: Add gpg-wks-client and gpg-wks-server.

* configure.ac: Add option --enable-wks-tools
* tools/gpg-wks-client.c: New.
* tools/gpg-wks-server.c: New.
* tools/gpg-wks.h: new.
* tools/wks-receive.c: New.
* tools/call-dirmngr.c, tools/call-dirmngr.h: New.
--

Note that this is just a starting point and not a finished
implementation.  Here is how to test the system using
foo@test.gnupg.org as example.

Prepare:

  mkdir /var/lib/gnupg/wks
  chmod o-rwx /var/lib/gnupg/wks
  mkdir /var/lib/gnupg/wks/test.gnupg.org

Run the protocol:

  ./gpg-wks-client -v  --send FPR USERID >x
  ./gpg-wks-server -v --receive  <x >y
  ./gpg-wks-client --receive <y >z
  ./gpg-wks-server -v --receive  <z

You should also setup a cron job to rsync
/var/lib/gnupg/wks/test.gnupg.org/hu/* to the webserver.

Signed-off-by: Werner Koch <wk@gnupg.org>

tools/call-dirmngr.h

@@ -0,0 +1,28 @@
+/* call-dirmngr.h - Interact with the Dirmngr.
+ * Copyright (C) 2016 g10 Code GmbH
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef GNUPG_TOOLS_CALL_DIRMNGR_H
+#define GNUPG_TOOLS_CALL_DIRMNGR_H
+
+void set_dirmngr_options (int verbose, int debug_ipc, int autostart);
+
+gpg_error_t wkd_get_submission_address (const char *addrspec,
+                                        char **r_addrspec);
+
+
+#endif /*GNUPG_TOOLS_CALL_DIRMNGR_H*/