Cross origin configuration support

[billchurch]

Versions < 0.3.0 do not have support for setting the COORS parameters for Socket.IO.

By default, Socket.io 2.2.x allows all hosts/ports as origin *:*.

[billchurch]

New config.json parameter http.origins takes a JSON object of authorized origins.

Defaults is localhost:2222

See https://socket.io/docs/v2/handling-cors/ for more details on how to use this.

If having trouble, consider enabling debug from an interactive shell for this app (will require full npm install and not production)

DEBUG=socket.io:server npm run start

Any origin errors will show up in a log statement like below:

socket.io:server origin http://localhost:2222/ssh/host/192.168.0.1 is not valid +2s