fix(users): Add user_type field in a form
fix(users): Add role select box

SD-1120
fix(roles): Show role in users table

Show error in users list if there is no role defined
Fix error in creating roles
feat(privileges): Add UI for extending user privileges
fix(users): fixing typos
Merge branch 'feat-privilege' of https://github.com/superdesk/superdesk-client into feat-privilege