HYDRASIR-404 A Profile Section should always be open/public

1. ProfileSection class overrides visibility to return public access right by default.
2. No Access Rights section is shown on the new/edit profile section form.
3. Updated existing specs to test for both of the above changes.
Merge pull request #484 from projecthydra/feature/HYDRASIR-404

HYDRASIR-404 A Profile Section should always be open/public