closes#9727
- this is a short term fix to proof that Disqus comments on preview pages no longer appear on other threads
- this is not a full solution to the problem
- the private API still returns /404/, which is right now inconsistent, but not critical in any way
- the url helper will now output the post preview url if you serve a draft/scheduled post
- this should register unique page urls at Disqus and ensure uniquness for threads
- i still don't understand why the cross posting happens at all, because we also pass an unique identifier to Disqus (the post ID)
- it could be that comments, which are added on the preview page, won't appear on the published urls, because
the published url !== preview url. I wasn't able to figure this out via testing or reading their docs
b335002269