[ci skip] Removed unnecessary word from Getting Started

Make sure :checkout_timeout and :dead_connection_timeout are numbers
Conflicts:
	activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb

Remove to_s from reflection.type in add_constraints

The instance var is already saved as a string in the initialization
method of AssociationReflection.

See https://github.com/rails/rails/blob/master/activerecord/lib/active_record/reflection.rb#L273

Fix after_commit warning message

Fix broken link to Upgrading Ruby on Rails Guide [ci skip]

in the 4.2 Release Notes [skip ci]

Change to link suggested by @zzak [skip ci]

Fixes #15821.

Add activejob guide to documents.yml [ci skip]

[ActiveJob] Add queue_name_prefix

fix broken link to rails blog [ci skip]

We can split queues on a per environement basis as well as seggregate per application so we can split queues on a per env basis

ActiveJob::Base.queue_name_prefix = 'foo'

Add option to stop swallowing errors on callbacks.

Currently, Active Record will rescue any errors raised within
after_rollback/after_create callbacks and print them to the
logs. Next versions of rails will not rescue those errors anymore,
and just bubble them up, as the other callbacks.

This adds a opt-in flag to enable that behaviour, of not rescuing
the errors.
    Example:
      # For not swallow errors in after_commit/after_rollback
      config.active_record.errors_in_transactional_callbacks = true

[fixes #13460]

If the request parameters are passed to create_with and where they can
be used to do mass assignment when used in combination with
Relation#create.

Fixes CVE-2014-3514

Conflicts:
	activerecord/lib/active_record/relation/query_methods.rb

Add a test case of nested empty array values in conditions

Fix rails-html_sanitizer in Gemfile template

[skip ci]