fixes #8874 - rework POT/PO updates for gettext 3's edit.po

3.1.13 adds an intermediate .edit.po file alongside each .po, which is meant
to be kept outside of SCM and updated by users, whereupon it's merged back into
the .po on the next rake gettext:find execution....

fixes #13236 - apply power operations to several hosts at once

This commit adds the ability to select multiple hosts and apply power operations
(reboot, shutdown, boot) to them.

Fixes #12720 - Add tabs for puppet on proxy show page

This patch adds two tabs to the proxy show page related to puppet
1. Puppet - this tab is for proxies managing a puppet master. This tab
displays information about the puppet master, such as number of classes...

fixes #13168 - permit safemode templates read-only access to AR relations

Templates such as kickstart_networking_setup use relations of
Host::Managed to access network interfaces. Since Rails 4, these return
relation objects rather than arrays which being core Ruby, had permitted...

Fixes #13171: Prevent frozen array error when plugins have assets

When the application is configured to serve static assets, the
public/asset paths of the plugins need to be added to the middleware
stack. However, this needs to occur prior to the middleware stack...

fixes #13144 - enable missing precompiled asset errors in test env

Remove extraneous ace/ace JS, which is included through vendor.

Fixes #11618 - Replace validation tests by shoulda-matchers

A good chunk of our unit tests are testing whether a validation is
working or not by testing it actively. For the validations we've
added ourselves I would say it's fine. However for validations that...

Fixes #13050 - Do not pass paths with /assets to helpers

Sprockets 3 does not recommend that, and the new option
`config.assets.raise_runtime_errors` on development.rb will raise errors
on development when doing it.

We only do it in one stylesheet and a helper, so fixing those let...

fixes #12612 - Update fog to 1.37.0

- Update fog to 1.37.0
- Add fog-vsphere
- Change detection if vmware provider is available

fixes #13039 - remove TemplateKind DB calls from UnattendedCtlr

UnattendedController created actions/methods during initialisation per
known TemplateKind, relying on the DB being populated. This caused
ordering issues when a plugin loaded the controller in a test...