Cloud session resume

[coneill-math]

Use a token to uniquely identify the session and enable resume after disconnect.

[dkahle]

habanero does this using cookies, but since the R session isn't coming through the browser, we'll need some other way to do this. IP logging?

[coneill-math]

I think a token string is the best way to go. The client can hand it to the Python dispatch server on first connection (or generate a random one if its the first time its connecting) and the dispatch server will either create a new instance or hand back the port of the existing session.