rename uri_name model to owner_name
rename user_groups display_name field to name (preserves index) and re-add display_name
use group name for building uri attributes and add owner_uniq_name to nameable module

Owner_uniq_name avoids clash with name attribute on user_groups
Merge remote-tracking branch 'cam/rename_uri_name_model' pull request

Conflicts:
	spec/controllers/api/v1/groups_controller_spec.rb