Apostrophe 3.3.1: hotfixes for relationships, and certain static localization texts

[boutell]

Apostrophe 3.3.1 has been released.

This is a hotfix release for a few bugs that rose to a level of urgency:

• In some situations it was possible for a relationship with just one selected document to list that document several times in the returned result, resulting in very large responses.
• Permissions roles UI localized correctly.
• Do not crash on startup if users have a relationship to another type. This was caused by the code that checks whether any users exist to present a warning to developers. That code was running too early for relationships to work due to event timing issues.