Made initial changes to controller and required upgrade of hydra-head -- tests needed.
WIP
Fixed something that was unintentionally broken.
WIP
WIP
WIP
Merge branch 'develop' into issue-217

Conflicts:
	app/models/ability.rb
	app/models/export_set.rb
	spec/controllers/export_sets_controller_spec.rb
Fixed #archive_manifest_row
Fixed test to use Digest::SHA256.digest to compare content strings