Fixes #17200 - Add option datacenter to compute resource

(cherry picked from commit e4c0449fbb71e65723c9daacc2f0d0e8a32989f0)

Fixes #16813 - improve error messages for associations

(cherry picked from commit ead67f0d679311187b6e6f9064a1d0bf3df70075)

Fixes #16633 - AuthSourceLDAP uses *_authenticators filters

Prior to this, non-admin users who were granted *_authenticators
permissions were not able to use them, as the controllers were looking
for *_auth_source_ldaps permissions instead.

(cherry picked from commit 8cc04d55c2cbe27a5c5fbb74254102f9d9658149)

Fixes #16681 - strong params in config groups API

(cherry picked from commit cc59b2a11892247974df34d21146089e4c75c406)

Fixes #16219 - Interfaces API works with scoped view_hosts

Before this commit, parent_scope called 'merge' on a scope that may
contain conditions that do not make sense on 'resource_class'.

In this case, when a user with a filter :view_hosts and search
'hostgroup_fullname = foo' tried to view...

Fixes #16397 - set nested template_combo. objects to optional

(cherry picked from commit d33fe9cd0e07b124e2ab5c87df7f8dfaefd24911)

Fixes #16461 - expose override in filter API

(cherry picked from commit 9bdc4fea9711290431b611337ac72c2003dc8efd)

Fixes #16380 - Eager load hosts attributes
Since Rails 4, in order to load delegated attributes,
we need to use 'eager_load' instead of 'includes'

(cherry picked from commit 7c5b8bd63f0fb7695b1b6e09a20e917004eca839)

Fixes #16415 - Accept unwrapped hash with 'layout' attribute

(cherry picked from commit eb9a7a4973790e27ba930640407eb77d7aa97d65)

Fixes #7806 - allow taxonomy association on role level