Cherrypick the refcount fixes and comments from mig-review.

I also find the revised "createPart2" values in *Lookup* calls appealing,
but I'm too fearful of breaking things without understanding the implications.
This approach just focuses on fixing the things I broke, without trying
to "fix" things long "broken" in multiple years of releases.
Cherrypick again.  Add test.
Fix for Bug 3602706.
Merge in fix for 3602706