Cleaned up meta-annotations.

There were some missing and some others not added to the
set of meta-annotations. I added the missing ones and
defined the set in such a way as to include them all, even
those which have not yet been born.
SI-6375, warn on lost annotation.

Annotations on abstract vals which are not meta-annotated
were silently discarded. Still discarded, only less silently.
I warned on as many "lost annotation" situations as I was
reasonably able to cover without false positives.
Tweaked meta-annotation error based on feedback.
Merge pull request #1803 from paulp/issue/6375

SI-6375, warn on lost annotation.