Engine: fixes #3318: Red Hat Repositories initial conversion

This commit contains initial changes to support the Red Hat Repositories
page in the UI.

It also has some changes for the 'old tupane' version of
providers/products/repos.  Although we'll be removing that in the
future, went ahead and updated the files since was in there anyway.
Engine: fixes #3314, 3317: Red Hat Subscriptions initial conversion
Merge pull request #3250 from bbuckingham/engine-redhat_hat_repos

Engine: fixes #3318: Red Hat Repositories initial conversion
Merge pull request #3249 from bbuckingham/engine-subscriptions

Engine: fixes #3314, 3317: Red Hat Subscriptions initial conversion
Engine: Fixes #3480: Correction to path for dashboard redirect.
Engine: Fixes #3326, 3327: Changesets & Changeset History initial conversion

Modifications to UI for Changesets and Changeset History to function
within an engine.
Engine: Dashboard: few fixes for syncs, content views and promotions
Merge pull request #3256 from ehelms/engine-fix-3480

Engine: Fixes #3480: Correction to path for dashboard redirect.
Engine: engine-users - fixes #3331
Merge pull request #3254 from thomasmckay/engine-users

Engine: engine-users - refers #3331
Merge pull request #3247 from bbuckingham/engine-changesets

Engine: Fixes #3326, 3327: Changesets & Changeset History initial conversion
Merge pull request #3260 from bbuckingham/engine-dashboard

Engine: Dashboard: few fixes for syncs, content views and promotions
Engine: Authorization: use ::User vs User

Updating references to User to explicitly point to the core
user (::User)
Engine: fixes #3332: Roles initial conversion

This is the initial conversion of the katello roles ui to work
within the engine.  This includes CRUD actions for roles
and permissions.
Merge pull request #3258 from bbuckingham/engine-roles

Engine: fixes #3332: Roles initial conversion
Engine: fixes #3479 - db:seeds fails if readonly role exists and is locked but role has no permissions