Added s-maxage, remove public

i. Our CDNs will use 's-maxage' to cache the resources.

ii. The clients will use the 'max-age' value.

iii. When we switch to Varnish (on a single domain) we either need to remove 's-maxage' on outbound requests or add the 'private' declaration.

In this regard I thinking the 'public' declaration is spurious.
Merge pull request #1065 from guardian/smaxage

Added s-maxage, remove public
Removed duplicate tests (cache-control is tested adequately in common)
Merge branch 'master' of https://github.com/guardian/frontend
Remove extraneous type attribute on analytics script tag
Tell older blackberries this is a mobile site
Merge pull request #1070 from guardian/old-blackberry-fix

Tell older blackberries this is a mobile optimised site
Editionalise Sport.

inadvertantly broke this
Merge pull request #1073 from guardian/sport-fix

Editionalise Sport.
Merge branch 'master' of github.com:guardian/frontend into dotcom