Role has name, not id
Make explicit the user was not found
Avoid empty user params
Fix response rendering for json and xml
Corrected routes description
Call to_json and to_xml explicitly
User instance has it's own formatting methods
Refactor controller and user
Add problem handling and fix deleting of user
Remove repeating code
Improve error handling
Modify save roles and groups
Add user id to params
Update id only if it does not exist
Use the correct params
Improve problem handling within the controller
Proposed corrections from jreidinger;
puts messages into brackets for gettext
Vim autoformat empty spaces
Add role name validation
Change input name for convenient param parsing