Added basic development principles
Merge branch 'master' of github.com:guardian/frontend into line-in-the-sand
Expired content uses new article design
Refactor dateline
Interactives use the new article layout
Refactor and BEMify headline lists
Whitespace
Top stories static page uses new article layout
Discussion page uses the new article layout
Simple advert format test bed

This gives us a basic system to deliver simple HTML adverts, Eg.

 http://localhost:9000/commercial/jobs
 http://localhost:9000/commercial/soulmates
 http://localhost:9000/commercial/...

As each one evoles in to something more complex we can split in to a seperate controller, as with travel offers.
Compare collections by id
One template per advert
Make the templates distinct from each other
Append dropped item to first preceding article
Style the group names
Style trails
Headline width
Remove collection ids
Always reload collection, even on failed save.
Non https callback for dev environments