Refactor user statuses, add status_name method
Add status_name to Principal

Add a status_name method to Principal, since some functions want to know user statuses on non-User Principals. The statuses are defined on the User, so these non-User Principals should always have the default status of 1.
Refactor users_status_options_for_select helper
Fix users index status filtering, status_name now returns string
Merge pull request #226 from opf/feature/rails3_refactor_user_status

Refactor user status