* Major rewrite of event streams

* If you used old event callbacks API, you need to switch to the streams API
    * See clixon_stream.[ch]
  * Old streams API which needs to be removed include:
    * clicon_log_register_callback()
    * subscription_add() --> stream_register()
    * backend_notify() and backend_notify_xml() - use stream_notify() instead
* Example uses "NETCONF" stream instead of "ROUTING"
* Added timeout option -t for clixon_netconf - quit after max time.

apps/backend/backend_client.h

@@ -52,19 +52,8 @@ struct client_entry{
     int                    ce_pid;   /* Process id */
     int                    ce_uid;   /* User id of calling process */
     clicon_handle          ce_handle; /* clicon config handle (all clients have same?) */
-    struct client_subscription   *ce_subscription; /* notification subscriptions */
 };
 
-/* Notification subscription info 
- * @see subscription in config_handle.c
- */
-struct client_subscription{
-    struct client_subscription *su_next;
-    int                  su_s; /* stream socket */
-    enum format_enum     su_format; /* format of notification stream */
-    char                *su_stream;
-    char                *su_filter;
-};
 
 /*
  * Prototypes