Problem: new function zmq_socket_get_peer_state not in zmq_draft.h

Solution: added function to zmq_draft.h

src/zmq_draft.h

@@ -141,6 +141,10 @@ int zmq_poller_modify_fd (void *poller, int fd, short events);
 int zmq_poller_remove_fd (void *poller, int fd);
 #endif
 
+int zmq_socket_get_peer_state (void *socket,
+                               const void *identity,
+                               size_t identity_size);
+
 /******************************************************************************/
 /*  Scheduling timers                                                         */
 /******************************************************************************/