provide a builder for form labels to customize wrapping around I18n content
Added enqueue_at support for QueAdapter in ActiveJob

* Added inline job runner for Que in test/support
* Updated QueAdapter to support enqueue_at
add I18n support for `:placeholder` HTML option is passed to form fields
just use the placeholder tag value if it is passed as a String
[ActionMailer] require activejob railtie
Merge pull request #16598 from seuros/master

[ActionMailer] require activejob railtie
Cache the value of `changed_attributes` when calling `changes_applied`

`changes_applied` calles `changes`, which will call `changed_attributes`
multiple times in a loop. This method actually performs work now, so we
should cache the results while looping over it when we know it cannot
change.
Clarify that unknown keys will become HTML attrs

Docs for all the other form tag helpers in this
file already clarify this.

[ci skip]
Remove erroneous form_tag option docs

This is true of the first param (url_for_options),
not of the second options param which is being
documented here.

[ci skip]
[ActiveJob] Add hook for test_framework and test templates
Merge pull request #16648 from seuros/master

[ActiveJob] Add hook for test_framework
Merge pull request #16602 from thetron/active_job_que_enqueue_at_support

Added enqueue_at support for QueAdapter in ActiveJob
Merge pull request #16647 from tjschuck/form_for_doc_options

Documentation update for form_for options
Use zero-padding for number_to_rounded_converter
Merge pull request #16650 from zzak/fix-precision-number_to_rounded_converter

Use zero-padding for number_to_rounded_converter
Properly referencing AR::RecordNotFound in AJ guide rescuing example
Merge pull request #16655 from brocktimus/20140823_doco_change

Correct AR::RecordNotFound in AJ guide rescue example [ci skip]
Fix example code in Active Job guide [ci skip]
Merge pull request #16659 from y-yagi/patch-4

Fix example code in Active Job guide [ci skip]
Update documentation to match change in #5942 [ci skip]