Format /roomauth results

Old:
![](http://a.pomf.se/urnwkq.png)

New:
![](http://a.pomf.se/otrrqp.png)

Still not perfect, but certainly more legible.
`.rank` getting generated from `groupsranking` sounds more logical, since it will be much easier to insert new groups.
I've actually done it already in my `config-refactor` branch: https://github.com/kotarou3/Pokemon-Showdown/blob/config-refactor/config/config-example.js