fixes #18476 - users have ssh keys

Fixes #18800 - strong params no longer breaks inherited attrs

Fixes #18813 - Sort matchers by priority

fixes #18681 - moves polymorphic subject into notification object

also adds host build, destroyed and missing owner UI notifications

Fixes #18767 - keep cloning info

Fixes #14013 - add a setting for default owner of new hosts

Fixes #14492 - Unify delete and minimize for dashboard widgets

Originally the idea was for the buttons to have a different effect on
the widgets, however with changes introduced later on these differences
have been reduced to being insignificant.

fixes #18662 - stop default scope being overridden by association

Ensure the Taxonomix empty default scope isn't overridden by association
scopes which (effectively) calls `.where(:id => ...)` and overrides the
value of :id set in this default scope. This occurs on Rails 5.0 which...

refs #16982 - remove User.current deassignment (no such user)

Allows the scope change to be reverted, as User.current is no longer set
to `nil` (there is no 'admin' user).

This was relying on a bug in Ruby on Rails 4.2 where the `unscoped` call
filtered through thread variables into Subnet.subnet_for which calls...

Fixes #17272 - Fixed Searches on parameters with !=