WebSocket timeouts to detect connection errors

[SpComb]

Exiting the tally/server will close the WebSocket TCP connection and immediately trigger onClose. Killing the network connection will leave the angularjs client dead with no error indication.

Detecting a loss of network connection needs some kind of websocket ping/pong mechanism.

angular-websocket has a initialTimeout/maxTimeout options, but these only seem to apply to reconnect operations.