Fixes #5821 - Capsule Content API/Backend
Fixes #5821 - Remove the fort engine

The code now uses mainly the Foreman's proxy logic + additional
support in Katello itself: not need to maintain separate engine just
for the node syncing
Fixes #5821 - address PR review issues
fixes #5857 - enclose sub-mgr args in quotes
Fixes #5852 - Updating gem dependencies

Removing foreigner since it's already required by foreman.
Fixes #5821 - add tests for capsule related features
Fixes #5821 - fix binding repository to the node
Fixes #5821 - add capsule content authorization
Fixes #5821 - add capsule content authorization tests
Fixes #4946/BZ1093601 - allow org-switcher urls to pass through angular.

This will prevent a redirect loop that occurs when switching orgs or
locations on a Bastion page.
Fixes #5768 Changed term system to content-host
Fixes #5703, prevent infinite loop on trailing slash.
updated all references from system to content host
Merge pull request #4137 from waldenraines/4946

Fixes #4946/BZ1093601 - allow org-switcher urls to pass through angular.
Merge pull request #4138 from waldenraines/5703

Fixes #5703, prevent infinite loop on trailing slash.
Fixes #5821 - better graceful handling of node binding/unbinding
fixes #5819 - host groups - fix the cross-link to activation keys page

This is a change needed after the 'single-page-app' changes went in.
Merge pull request #4143 from bbuckingham/issue-5819

fixes #5819 - host groups - fix the cross-link to activation keys page
Merge pull request #4118 from iNecas/capsule-api

add capsule support to API/CLI
Merge pull request #4144 from jlsherrill/iNecas-capsule-api

Fixes #5821 - add capsule support to API/CLI