Plinth UI overhaul

Created by: mray

I think plinth is lacking behind other comparable projects like cozy.io or nexcloud/owncloud in terms of a ui. It currently is a vanilla boostrap and "does the job", but could do much better.

I plan to work on a new iteration an would like to gather feedback

• what are problems you would like to see adressed?
• what do you consider to be good inspirations for a next UI iteration of plinth?