Re-instate the "edit only latest" logic

- Added methods to the api service to allow retrieving latest version, as well
  as determining if the currently selected version of an API is the latest.
- Modified RPC and REST indexes to only show edit/delete buttons when the
  current verions is the latest.
Rebuild distribution
Merge branch 'hotfix/edit-only-latest'

Re-instate the "can edit only on the latest version" logic.