Make Links Clickable

Closes #328.
actually, checking for the type of something is often a code smell. In this case it is a correct code smell, because the correct place to put this logic is in the specific function that renders chat messages. We already dispatch on `type` in `getEventMessageHtml`.

```js
  chat: function(ev) {
    return ev.text;
  },
```

change to

```js
  chat: function(ev) {
    return linkify(ev.text);
  },
```

No if statement necessary :D