Content sponsorships now work without JS

Also, content with multiple sponsors will be identified, but the sponsors names will be hidden to avoid clashing. 
Could do a fold:
`tags foldLeft(0){(soFar, numSponsors) =>`
`soFar + tagToSponsorsMap.getOrElse(tag.id.split("/").last, 0)`
`} > 1`
or something like that, but not sure it's any clearer.