fixes #12746 - list compute resources from plugin definitions

Load the full list of known CRs from plugins on the fly, instead of
modifying the class-level list of supported plugins. Since plugin
definitions don't get reloaded, this allows the ComputeResource class to...

Fixes #14038 - pass corespersocket in VMWare image-based provisioning

fixes #9782 - implement mediapath for suse/yast

Fixes #14326 - Show long compute resource descriptions correctly

fixes #12962 - Add Xenserver to list of supported OS families.

Templates are included in community-templates repo.

Fixes #13727 - Error raised when setting default_value when override is set to false

Fixes #14166 - Host facet attributes handling updated

Basically added code to include handling of host facets in hosts where
no form attributes belonging to that facet are set.

Fixes #14252 - Redirecting to edit taxonomy page if no hosts to assign

Fixes #14298 - fix popover on facts page

Fixes #12979 - Create helper for "new" button

Previously the button classes were applied to new buttons using jQuery.
This commit creates a `new_link` helper that makes sure all new buttons
will receive the correct class and only display if authorized. Also a...