Order rooms alphabetically preference

Defaults to order by user count
can change preference with /order or by using the drop down in the options menu
Changing ordering preference forces the Rooms room to update.

![options](https://cloud.githubusercontent.com/assets/7889474/3717014/c005fb52-161d-11e4-869c-eff4cb2cce50.jpg)

Ditto here. Default `order` should be a string, not `{}`.

You could also just leave it blank. I'd actually suggest leaving it blank. You don't need a default.