Issue 3995: And X more kudos message should be correctly pluralized

Resolves issue: https://code.google.com/p/otwarchive/issues/detail?id=3995

Checks to see how many remaining Kudos there are. If there is only 1, it says "user" otherwise it says "users". 


As mentioned in the ADT meeting, the %{} syntax only works inside an interpolated string. Additionally, the string here is constructed according to the syntax rules of English, which might not apply to other languages (in French, for instance, the translation for "more" would go after the "utilisateur/s"). It would probably be better for both alternatives to be present as separate ts() items, something like this:

```ruby
collapsed_count = kudos.length - ArchiveConfig.MAX_KUDOS_TO_SHOW
if collapsed_count == 1
  ts(" and 1 more user")
else
  ts(" and #{collapsed_count} more users")
end
```

Probably still doesn't cover all bases (like languages with a dual form as well a singular and plural :confounded:), but at least it would work for language where the syntax might vary along with the plurality.