Improvement/ping pong

I need to test this first (since it has jasvascript changes), but I think it's a good idea to move the pinging from server to client to keep the connection alive.

Changes:
* Improved ws-reconnecting.js send() error handling: It did not really buffer up and resend messages like it used to.
* Bumped Mojo::Redis to 0.9926 to get on(message => $channel => ...)
* Remove CONVOS_PING_INTERVAL: The client will do keep-alive
* Change ws timeout in server to 30 and client keep-alive to 10 seconds
* Add super basic "/ping" command