#2309 When editing a blog post, don't change author
Don't change the author when changing a blog post. Particularly, test creating a blog post, then log in as different admin and set the post to draft and then back to published. That will trigger a new feed item (use [[neighborhood_feeds tool_name=blog max_number=6 sort=pubdate]] macro) and it should have the original author still.
code on forge:wo/2309. Also addresses Feed item authorship. For blog posts, the author of the feed item is now the original author of the post.
This approach has a flaw, but hopefully one we can live with. It protects the author in case of changing draft to published and back, but also discounts edits to the actual text of the blogpost by later authors. The original author is the canonical author regardless of changes. This fix was easy. Fixing it to take actual changes into account would be significantly harder.
Rebased and merged to dev, code review looks good, tested ok as well.