Article integration

- Cleaned up ArticleResponseMaker. Removed transformer options and
moved them inside a dedicated ArticleTemplateTransformer
- ArticleNavigationTransformer will now provide context sensitive
links. One type for mobile and one for web
- New ArticleTemplateTransformer to transform the article values that
would usually be removed by the articleTransformer but are needed for
the templates
- ArticleTransformer will now provide context sensitive links. One type
for mobile and one for web
- SponsorTransformer now returns all media attributes as they are
needed for the front end templates
- New VideoTransformer to transform article video data
- Reformatted constants. New constant for deviceBaseUrl
- Tidied up article controller
- New helper function to enable items to be inserted into any position
of an associative array
- New IOC bindings
- New linkMaker to produce device friendly links
- New article/video relationship
- Removed unwanted (and empty) function from ArticleRepository. Related
articles now only returns 5 items
- New Video model
- composer.json updated to autoload linkMaker.php