wish list of suggestions for the reviewer database and invitation email

A few suggested improvements (from the point of view of an action editor) regarding how JMLR keeps its database of reviewers, and how invitation emails are sent.

1. I often find reviewers that appear as duplicate accounts. It would be nice to have a unique account per reviewer. One reason (probably the main one) why duplicate accounts occur is because AEs create a new account for an existing reviewer who has changed email address. The system doesn't allow to update a reviewer's email address.

2. To add an extra address as .cc when inviting a reviewer. Sometimes I'm not sure whether the address in the system works and I'd like to add an alternative one.

3. To have the JMLR system let me know if an email address is not working (when inviting a reviewer). Sometimes reviewers don't respond to an invitation and it might be that the address doesn't work. I can email directly to the address to find out, but it would be best to know as soon as the system sends the invitation (by getting a bounced message).

The issue names no files or tests; start by locating the reviewer-account and invitation-email entry points in the JMLR webpage. Clarify whether the scope covers separate changes for updating email addresses without duplicate accounts, adding CC recipients, and reporting bounced invitations; done requires agreed behavior and tests for each.