Official proportions for Red/System icon, include all formats

This lays out a distinct proportionality for the Red/System logo, and as a fringe benefit...you now have a scalable and cleaned up avatar file:

![New Avatar](https://raw.githubusercontent.com/hostilefork/branding/master/red-system/red-system-color-128x128.png)

Looks better than:

![Old Avatar](http://i.stack.imgur.com/l68fH.png)