Add base css to the head
Remove duplicate extends from head.scss
Merge branch 'master' of github.com:guardian/frontend into optimise-css-head

Conflicts:
	common/app/assets/stylesheets/module/trails/_trail.scss
Clean syntax
Fix styling regressions
Separate r2 comment styling from head
Merge branch 'master' of github.com:guardian/frontend into optimise-css-head
Merge branch 'master' of github.com:guardian/frontend into optimise-css-head
Follow BEM conventions and trim how title attributes are populated by relative timestamp script
Merge pull request #1097 from guardian/optimise-css-head

Optimise css head