Very simple clientside Aus edition.

Based on our preference framework it modifies links to the network front if you have opted into AUS.
Merge branch 'master' of github.com:guardian/frontend into australia
Better handling of multiple edition links on the same page
Add initial custom query for trailblock description
Merge branch 'aus-front' into custom-query

Conflicts:
	front/app/controllers/front/Front.scala
Merge branch 'aus-front' into custom-query
Merge branch 'master' into custom-query
Remove australia specific code
Add new case classes ItemTrailblockDescription and QueryTrailblockDescription
Introduct new trait TrailblockDescription
Merge branch 'master' into custom-query

Conflicts:
	common/app/common/ContentApiClient.scala
Remove test query from Uk culture
Add type signatures
Fix id for Uk comment is free query
Merge branch 'master' into custom-query
Remove edition from TrailblockAgent
Introduce a temp Au object to be used with ItemTrailblockDescription
Remove custom query, split out trait for use in edition objects
Update Uk object with comment query
Merge branch 'master' into custom-query
Clean imports, add query to US front