Bug 1102849 - Register and show events of a Room

You can do this _eventsSectionEntries.innerHTML = ''; here https://github.com/mozilla-b2g/firefoxos-loop-client/pull/385/files#diff-f9f543a9930bda639eaa7b7d0827ffb3R182

```js
Navigation.to('room-detail-panel', 'right', function() {
  _eventsSectionEntries.innerHTML = ''
});
```