Add permissions handling for metadata file upload
Merge pull request #483 from duke-libraries/iss429

Add permissions handling for metadata file upload
initial work on upgrade to Rails 4
Squashed hydra-head 7 deprecations.
Merge pull request #484 from duke-libraries/squash-hh7-deprecations

Squashed hydra-head 7 deprecations.
switch to strong parameters instead of protected attributes; couple of deprecation fixes
Adds superuser status:
- Method :superuser? added to User class
- Method :superuser_group added to GroupService
- DulHydra.superuser_group config setting added -- defaults to env var value
- Ability class overrides hydra_default_permissions to grant :manage, :all if current_user is superuser
- DulHydra.extra_ability_logic config setting removed -- using Ability#custom_permissions instead, as Hydra::Ability intends.
Merge pull request #486 from duke-libraries/superuser-permissions

Adds superuser status
Fixed XhrRequestConstraint.
Marked XHR routing specs as pending b/c don't know how to mock Ajax header.
Merge pull request #487 from duke-libraries/iss228

Iss228
Merge branch 'develop' into issue-470