dirmngr: New command AD_QUERY.

* dirmngr/dirmngr.h: Include name-value.h
(struct server_control_s): Add rootdse and rootdse_tried.
* dirmngr/dirmngr.c (dirmngr_deinit_default_ctrl): Release them.
* dirmngr/ks-engine.h (KS_GET_FLAG_ROOTDSE): Add two new flags.
* dirmngr/ks-engine-ldap.c: Include ks-action.h
(SERVERINFO_GENERIC): New.
(struct ks_engine_ldap_local_s): Add scope.
(ks_ldap_new_state): Set a default scope.
(ks_ldap_clear_state): Ditto.
(my_ldap_connect): Add flag generic.
(return_all_attributes): New.
(fetch_rootdse): New.
(basedn_from_rootdse): New.
(ks_ldap_get): Move some code out to ...
(ks_ldap_prepare_my_state): New.
(ks_ldap_query): New.
* dirmngr/ks-action.c (ks_action_parse_uri): Factored out from server.c
(ks_action_query): New.
* dirmngr/server.c (make_keyserver_item): Factored most code out to
ks_action_parse_uri.
(cmd_ad_query): New.

* dirmngr/ks-engine-ldap.c (no_ldap_due_to_tor): New common error
printing.  Now also with status line.
--

This command allows to query the Windows Active directory.

(cherry picked from commit 625aeb65b0)

no_ldap_due_to_tor has been backported from 2.4

dirmngr/dirmngr.h

@@ -36,6 +36,7 @@
 #include "../common/sysutils.h" /* (gnupg_fd_t) */
 #include "../common/asshelp.h"  /* (assuan_context_t) */
 #include "../common/i18n.h"
+#include "../common/name-value.h"
 #include "dirmngr-status.h"
 #include "http.h"     /* (parsed_uri_t) */
 
@@ -230,9 +231,12 @@ struct server_control_s
   int audit_events;  /* Send audit events to client.  */
   char *http_proxy;  /* The used http_proxy or NULL.  */
 
+  nvc_t rootdse;     /* Container wit the rootDSE properties.  */
+
   unsigned int timeout; /* Timeout for connect calls in ms.  */
 
   unsigned int http_no_crl:1;  /* Do not check CRLs for https.  */
+  unsigned int rootdse_tried:1;/* Already tried to get the rootDSE.  */
 };
 
 
@@ -251,6 +255,8 @@ void ks_hkp_reload (void);
 
 
 /*-- server.c --*/
+void release_uri_item_list (uri_item_t list);
+
 ldap_server_t get_ldapservers_from_ctrl (ctrl_t ctrl);
 ksba_cert_t get_cert_local (ctrl_t ctrl, const char *issuer);
 ksba_cert_t get_issuing_cert_local (ctrl_t ctrl, const char *issuer);