Present both possible URL options as separate copy/pastable options

Currently the default URL message given on the console on startup is:

---
Copy/paste this URL into your browser when you connect for the first time,
to login with a token:
     http://(myip.com or 127.0.0.1):8888/?token=8fdc8 ...
---

This will always need editing to use. Replace with one host IP (e.g. 'myip.com')
option and one local ip (127.0.0.1) option to make it copy/pastable again.

notebook/notebookapp.py

@@ -1439,7 +1439,9 @@ def display_url(self):
         if self.token:
             # Don't log full token if it came from config
             token = self.token if self._token_generated else '...'
-            url = url_concat(url, {'token': token})
+            url = (url_concat(url, {'token': token})
+                  + '\n or '
+                  + url_concat(self._url('127.0.0.1'), {'token': token}))
         return url
 
     @property