Deleted the "freshness" diagnostics.

They told us what we need to know, in summary, 1 in about 300 requests is slightly stale.
Merge branch 'master' of github.com:guardian/frontend into freshness
Removing close that isn't needed
Remove unused dark gallery cta variant
Convert spacings with gutter to gs-gutter
Change gutter dimensions to gs-gutter
Remove unused classes that use gutters
Improved logic of showing comments
Extremes added to pagination
Getting out of the gutter
add ResponsiveNavSwitch
add DOM structure for the responsive navigation redesign
Merge branch 'master' nto webdriver-minorfix

fixing merge conflict hopefully
Easy reading and touching on pagination
Merge branch 'master' of github.com:guardian/frontend into pagination-extremes
Merge pull request #4867 from guardian/discussion-gutter

Getting out of the gutter
Easy reading paginating
default, not defaults
Merge pull request #4852 from guardian/freshness

Remove "Freshness" metrics
Merge pull request #4863 from guardian/deprecate-gutter

Deprecate $gutter in gallery and states