Fix dependant => dependent
Remove EqualsPatternClass.

Detritus from the classic pattern matcher, which was recently
removed 6084d2d9.
Merge pull request #1896 from retronym/topic/remove-equals-pattern-class

Remove EqualsPatternClass.
Merge pull request #1837 from julio/fix-typo

Fix dependant => dependent
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.