Fix bug where hibernating laptops fail to restart the event stream.

On some devices, the act of hibernating black holes the request so the
success/failure callbacks never fire. This prevents a re-poll as that is done
in the callbacks. To fix this, we add a local timer which, when it fires,
will forcibly do a re-poll. The local timer has a timeout value several
seconds more than the timeout= value (which should've returned by then).

lib/client.js

@@ -1053,10 +1053,22 @@ function _pollForEvents(client) {
     if (!client.clientRunning) {
         return;
     }
+    var discardResult = false;
+    var timeoutObj = setTimeout(function() {
+        discardResult = true;
+        _pollForEvents(client);
+    }, 40000);
+
     client._http.authedRequest(undefined, "GET", "/events", {
         from: client.fromToken,
         timeout: 30000
     }).done(function(data) {
+        if (discardResult) {
+            return;
+        }
+        else {
+            clearTimeout(timeoutObj);
+        }
         var events = [];
         if (data) {
             events = utils.map(data.chunk, function(event) {
@@ -1120,6 +1132,12 @@ function _pollForEvents(client) {
         }
         _pollForEvents(self);
     }, function(err) {
+        if (discardResult) {
+            return;
+        }
+        else {
+            clearTimeout(timeoutObj);
+        }
         self.emit("syncError", err);
         // retry every few seconds
         // FIXME: this should be exponential backoff with an option to nudge