Fixes #5719 - make pulp async actions cancellable

The cancelling is done though the task details: running steps tab
fixes #4636 - refactor OperatingsystemExtensions to RedhatExtensions and refactor MediumExtensions
Fixes #5719 - poll directly after sending the cancel
Fixes #6237 - allow canceling remote execution actions
Fixes #6249,BZ1109398: Candlepin proxy routes properly looking up organization.

When the API switched to looking up organization by ID, the Candlepin
proxy routes that required an organization broke since subscription-
manager GUI and CLI pass the organization label and not numerical ID.
Fixes #4172: Prevent alch-edit-select errors by checking if editTrigger exists.
Fixes #6246, bz1100582 - Services mods for  KS templates

Some of the services like sendmail,cups,pcmcia were unecessarily
disabled. Removing them from being disabled.
Fixes #6256 - Handle a nil value in kt_env for hostgroups
Fixes #6252/BZ1087079 - default to errata_id on bulk errata searches.
Fixes #5451: Load only custom products for repo discovery.

Adds 'custom' param option to the products index API call in order
to retrieve non-red hat products. Updates the repo discovery creation
screen to pass custom so that users are only creating repositories
for existing custom products.
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
fixes #6144 - fix css formatting formatting fields on katello form builder to bootstrap3
fixes #6145 - add pulp proxy to host form
fixes #6269 / BZ 1110486 - activation key - include description on details pane

Add the description to the 'details' pane to support review/edit.
Merge pull request #4297 from bbuckingham/issue-6269

fixes #6269 / BZ 1110486 - activation key - include description on details pane