r13609: Get in the initial work on making ldb async

Currently only ldb_ildap is async, the plan
is to first make all backend support the async calls,
and then remove the sync functions from backends and
keep the only in the API.

Modules will need to be transformed along the way.

Simo

source/libcli/ldap/ldap_client.h

@@ -42,8 +42,10 @@ struct ldap_request {
 	DATA_BLOB data;
 	struct {
 		void (*fn)(struct ldap_request *);
-		void *private;
+		void *private_data;
 	} async;
+
+	struct timed_event *time_event;
 };