switch default ws_url logic to js side
In some cases (proxies, #3305), the request object doesn't have the right information about the originating information. This changes the default behavior, so that ws_url is generally empty by default, which the javascript takes to mean 'the same as http'. This is simpler and should be more resilient than trying a guess on server-side.
also replaces unused websocket_host with websocket_url
Rather than specifying only the hostname, it makes much more sense to specify the whole protocol,host,port in a single go.
In some cases (proxies, #3305), the request object doesn't have the right information about the originating information. This changes the default behavior, so that `ws_url` is generally empty by default, which the javascript takes to mean 'the same as http'. This is simpler and should be more resilient than trying a guess on server-side.
instead of random.
The random cookie name meant that every time you restarted the notebook it would get a new key in the cookie for the same host, resulting in an ever-growing cookie full of obsolete data.
Matthias Bussonnier
MinRK
Brian E. Granger