Expose Sponsor in DfpAgent

This makes it possible to determine the sponsor of
pages with sponsorship badges,
ie sponsored pages and advertisement features.
updated to latest
Merge branch 'master' into kc-sponsor
Remove unused test-tc script
Remove unused integration-tc script
removing progressbar animation
Reduce disk usage during dist
Merge pull request #4779 from guardian/dist-disk-usage

Reduce disk usage during dist
add new 940x230 banner size
Merge pull request #4781 from guardian/new-banner-slot-size

Add new 940x230 banner size
fix test
Merge pull request #4782 from guardian/new-banner-slot-size

Fix test
Merge pull request #4775 from guardian/remove-old-test-tc

Remove unused team city scripts
Reset dfpRoot for dev environments to test-theguardian.com
Fix grunt watch task for Sass compilation
Add JS and CSS for video preroll countdown labelling
Merge pull request #4783 from guardian/preroll-countdown

Preroll countdown
Merge pull request #4780 from guardian/removing-progress-animation

removing progressbar animation
Merge pull request #4759 from guardian/kc-sponsor

Expose Sponsor in DfpAgent
fix for broken progressbar