Include Section in Sponsor Logo Targeting

If a section is targeted, this will be honoured
in decision to open logo ad slot.
Spread Out Sponsorships Slightly in Admin Report
Remove Redundant Ad Call Parameter

'cat' is never used.
Modify Implementation of Sponsorship Sections

Now derive section from targeted ad units
because these are what Ad Ops target, not sections directly.
Merge branch 'master' into kc-sponsor-section
Fix Broken Test Fixture
Fix Another Broken Test Fixture
Cater for Ad Units Targeting Site Root
Remove Default Value from Sponsorship Status
Merge pull request #6292 from guardian/kc-sponsor-section

Open Sponsor Logo Slot for Right Keyword