Expose addr instead of param on complete/update/stop

[lorentzkim]

Instead of only exposing addr, I think it'd be more flexible to expose the entire params (at server.js:225, line that does self.emit(common.EVENT_NAMES[params.event], params.addr)) so you can do more intricate processing.

Specifically, peer_id and announce url would be exposed rather than addr alone, and would make handling individual downloaders and torrents a lot neater for applications that need that level of complexity.

I am aware of this possibly breaking API since other modules rely on it; is there a decent solution to expose it?

[feross]

We can expose it as a second argument on the events:

server.on('update', function (addr, params) {

})

Released as version 4.5.0.