fixes #4636 - refactor OperatingsystemExtensions to RedhatExtensions and refactor MediumExtensions
Fixes #6252/BZ1087079 - default to errata_id on bulk errata searches.
Fixes #6258 - env_id & cv_id optional in ak update

Activation Key update should allow passing of environment_id and
content-view to be optional since creation allows the existence
of Activation Keys without a lifecycle-environment or content-view
asociated.
Fixes #6260/BZ1023881 - display OS on content host index page.
Merge pull request #4291 from waldenraines/6252

Fixes #6252/BZ1087079 - default to errata_id on bulk errata searches.
Merge pull request #4290 from dustint-rh/ak_put_env_not_required

Fixes #6258 - make env_id optional in ak update
Merge pull request #4292 from waldenraines/6260

Fixes #6260/BZ1023881 - display OS on content host index page.
Merge pull request #4246 from isratrade/6156

fixes #4636 - refactor OperatingsystemExtensions to RedhatExtensions and refactor MediumExtensions