signaler.cpp's Windows Lock should be in the "Global" namespace

That way it can be used more appropriately between processes.

src/signaler.cpp

@@ -249,9 +249,9 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
     //  Note that if the event object already exists, the CreateEvent requests
     //  EVENT_ALL_ACCESS access right. If this fails, we try to open
     //  the event object asking for SYNCHRONIZE access only.
-    HANDLE sync = CreateEvent (&sa, FALSE, TRUE, TEXT ("zmq-signaler-port-sync"));
+    HANDLE sync = CreateEvent (&sa, FALSE, TRUE, TEXT ("Global\\zmq-signaler-port-sync"));
     if (sync == NULL && GetLastError () == ERROR_ACCESS_DENIED)
-      sync = OpenEvent (SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE, TEXT ("zmq-signaler-port-sync"));
+      sync = OpenEvent (SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE, TEXT ("Global\\zmq-signaler-port-sync"));
 
     win_assert (sync != NULL);