[WIP] First pass of Car Campaign landing page
[WIP] Second pass of Car Campaign build

All media queries in place and build is now as per design. Some minor
formatting issues in IE8.
Rename l-car-landing class prefix to l-car-campaign

Move _car_campaign.scss into layout directory
Add full width background gradient.
Add generic section-media class for controlling media width
Fixes for IE8
Widen the $mq-m view grid on Car Campaign page
Fix image cutoff of bottom image on Car campaign in IE8
Fix gradient BG appearing above main site header on Car campaign page in IE11
Tweak the image positioning on Car campaign page
Add Car costs calculator URL to Car campaign page
Format Car campaign SCSS
tokenize car campaign translations
add welsh translations for car campaign
add welsh links to car campaign
Improve Car campaign CSS formatting
Remove unnecessary bottom padding on Car campaign
Move Car campaign page-bg into $mq-xl media query

So that it is more obvious that this only affects this media query
Rename car_landing directory to car_campaign
Optimise car campaign images
update title tag in car campaign