UI to manage API users

www.agileplannerapp.com/boards/173808/cards/4993

introducing a UI to:
1. list, create, edit, suspend API users
2. create, revoke and regenerate tokens for API users

see commit messages for additional information.
'twas a copy-paste from the `:user` factory above. i'm not too keen about making DSL code like this, look like other code. nevertheless, corrected it.