Remove unused discussion mixins
Remove unused release class
Remove unused  ad-slot-top-banner-ad
Load styles for the show more button as global styles
Load only the needed facia container layouts depending on the application
Release message kicks in with JS so can be loaded in global.css
Load tones only in content pages
Various fixes
Merge pull request #4630 from guardian/lean-css

Lean Head CSS (and remove some unused classes)