Investigate chat options

[stefanoborini]

Investigate what you can do with the chat. Do not implement it, just perform some research on what we can use to power the chat.

This will probably need #497

[martinRenou]

We can set a Websocket with tornado (http://www.tornadoweb.org/en/stable/websocket.html#) and use Javascript built-in WebSocket class.

I tried to make it work without success, I'll try again soon.

For the web interface, we can use the AdminLTE chat widget. We just need to decide where to put it. And we should maybe use a notification menu for new incoming messages.

[stefanoborini]

There's no chance we can reinvent a chat system from websockets. The purpose of this issue is to find something that we can plug in easily.

[martinRenou]

I cannot find something pluggable to tornado. I think the better solution would be to implement something like this: https://github.com/tornadoweb/tornado/blob/master/demos/chat/chatdemo.py

In this example they use jQuery for doing request to the server. I wonder if we can use jsonApi and devour for the chat.