Allow persons to be converted to users
In order to allow "persons" (in particular those with accepted papers) to get user access to the platform (to edit their special session abstracts, upload materials, buy tickets for contributors - see #232 (closed) ), they should be offered an user account.
It needs to be researched and defined if this process is to be done automatically (requires development) or if manual intervention from the LOC is required (e.g. by exporting CSV lists from the reports section). Opinions on this are welcome, especially from @mladen @ponder @viktoriya.kulikova
- Remove person duplicates via rake task
- Create rake task for creating user accounts for people with accepted papers and no user account (user.id is nil) (adapt logic from app/models/person.rb#265)