Handle connection losses more gracefully by throttling reconnections.

At the moment, if the bot is disconnected from a server in a way that fires a connection lost event, the bot will instantly try to reconnect. This is especially problematic as it will also happen with kills or disconnects because of throttled connections. Instead of this behaviour, make it so that it tries immediately once, then retries after `x minutes * n`, where `n` is the number of retries.