Fix punctuation
Improve schema integrity check

The schema integrity check was only testing in one direction and so
was missing some types of errors. In particular where there
were leftover fields in the versioned release schema.
Clean up versioned-release-schema w/ improved test

Having improved the test for the versioned release schema, there were a few
bugs lurking around. These have now been cleaned up and the schema updated.
This wasn't a big clean up.