Add new dashboard layout to PIwik 1.8.3


I am using PIwik 1.8.3 and am really liking the new selectable dashboard layouts,

In the past i restyled Piwik so as the dashboard was more to my liking…

i would like to have a large widget area at the top and then either 2 or 3 columns underneath this.

This was easy enough to achieve by editing the template file of the dashboard plugin on old versions, I can’t get my head around the new method in the latest version of piwik though.

I think it would be great if i could add 2 new layouts to the selector…

Could anybody point me in the direction of what files i would need to edit to add a new dashboard layout type ?

Where abouts are the layouts generated and stored ?

Any help with this would be much appreciated