fix(console): the console daemons log where the operator looks

- novncd and socketiod log to stderr: the journal on hosts, docker logs in
  the container (runit no longer sends them to unrotated files under
  /var/log). Django's settings gave them the panel's own log file, which
  every process rotated on its own, and made novncd's -v and -d have no
  effect; both work again.
- A refused console says why in the log: novncd's denials are warnings
  (they were shown only with -v), socketiod logs each refusal and who
  opened which VM's serial console.
- The README's serial console notes say what #228 changed (access
  re-checked, superuser takeover, reasons) and where the logs are.

console/tests/test_views.py

@@ -577,12 +577,13 @@ class NovncdDaemonLogicTestCase(TestCase):
         handler.msg = MagicMock()
 
         socket_factory = MagicMock()
-        # Should cleanly exit and log message without raising UnboundLocalError
-        handler._new_client(socket_factory=socket_factory)
+        # a refusal is a warning: it shows in the log without -v
+        with self.assertLogs(level="WARNING") as log:
+            handler._new_client(socket_factory=socket_factory)
 
         mock_get_info.assert_not_called()
         socket_factory.assert_not_called()
-        handler.msg.assert_called_with("No console token in the websocket URL")
+        self.assertIn("without a token", log.output[0])
 
     @patch("console.tokens.authorize")
     @patch("vrtManager.instance.wvmInstance")