Pagination, langs

- Created new PageMaker class to paginate result sets from DB calls
- Reverted ArticleTransformer to only return a single media item rather
than an array
- Started to centralise all API string responses within a language file
- Updated routes for listing to remove timestamp as a URI segment. This
is now picked up as part of a query string submission
Amends

- PageMaker class now looks for query string params
- Removed query string check from controller as now handled my
PageMaker class