Fixes #5719 - make pulp async actions cancellable

The cancelling is done though the task details: running steps tab
Fixes #5719 - poll directly after sending the cancel
Fixes #6237 - allow canceling remote execution actions
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 #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 #6144 - fix css formatting formatting fields on katello form builder to bootstrap3
fixes #6145 - add pulp proxy to host form
Fixes #6239: Ensure product label and name uniqueness is adhered to.
Fixes #4847: Add loading spinner for environment selector on promotion page.
fixes #6262 - wraps system name display to prevent overlapping in table, BZ 1019773
Merge pull request #4285 from ehelms/fixes-4172

Fixes #4172: Prevent alch-edit-select errors by checking if editTrigger ...
Merge pull request #4293 from cfouant/fixes-6262

fixes #6262 - truncates system name display to prevent overlapping in table, BZ 1019773
Merge pull request #4289 from ehelms/fixes-4847

Fixes #4847: Add loading spinner for environment selector on promotion p...
fixes #6064 - Content-view filters can be sorted by name, BZ 1102451
Merge pull request #4286 from ehelms/fixes-6239

Fixes #6239: Ensure product label and name uniqueness is adhered to.
Merge pull request #4276 from cfouant/fixes-6064

fixes #6064 - Content-view filters can be sorted by name, BZ 1102451
Merge pull request #4238 from iNecas/issue/5719

Fixes #5719 - make pulp async actions cancellable
Fixes #5523: Content host available releases are now calculated based on content view.