* https://github.com/guard/listen/releases/tag/v3.2.0
* https://github.com/guard/listen/issues/465
* `listen` removed the unmaintained `ruby_dep` dependency, which
  incorrectly shows warnings when running on TruffleRuby.

I changed `load_defaults` to `config.load_defaults` in the guide
to emphasize its context,
sorted headers "With 'x.x'" in descending and rephrased them
to "With 'x.x', it includes previous versions' new defaults"
and documented the method on https://api.rubyonrails.org.

    class SensitiveJob < ApplicationJob
      self.log_arguments = false

      def perform(my_sensitive_argument)
      end
    end

When dealing with sensitive arugments as password and tokens it is
now possible to configure the job to not put the sensitive argument
in the logs.

Closes #34438.

Add configuration option to turn off drawing of Active Storage routes.

Assigning to a collection of attachments appends rather than replacing, as in 5.2. Existing 5.2 apps that rely on this behavior will no longer break when they're upgraded to 6.0.

For apps generated on 6.0 or newer, assigning replaces the existing attachments in the collection. #attach should be used to add new attachments to the collection without removing existing ones.

I expect that we'll deprecate the old behavior in 6.1.

Closes #36374.

The robots.txt site is moved permanently to https URL.

I changed return value of `ActionDispatch::Response#content_type` in #36034.
But this change seems to an obstacle to upgrading. https://github.com/rails/rails/pull/36034#issuecomment-498795893

Therefore, I restored the behavior of `ActionDispatch::Response#content_type`
to 5.2 and deprecated old behavior. Also, made it possible to control the
behavior with the config.

Ref: bcf370d6, 06ab7b27.

'Week day' has a specific meaning in English -- see https://en.wiktionary.org/wiki/weekday for details -- that is not meant here.  'Day of week' is more appropriate.

[ci skip]

[skip ci] The default value of config.active_record.collection_cache_versioning without loading Railtie is false

Please check https://github.com/rails/rails/pull/36260#discussion_r283266942 for reference.

[Vishal Telangre, bogdanvlviv]

References:

- https://github.com/rails/rails/commit/4f2ac80d4cdb01c4d3c1765637bed76cc91c1e35
- https://github.com/rails/rails/blob/b1c917ee2fdaa452aeb52904db0d254d85285380/railties/lib/rails/application/configuration.rb#L147-L149

Clarify that both `config.action_controller.perform_caching` and
`config.action_mailer.perform_caching`'s default are `true`. This
default is set in `AbstractController::Caching`.

One can verify this by commenting out all

```
@controller.perform_caching = true
```

in `actionpack/test/controller/caching_test.rb` and run the tests. They
should still pass.

[skip ci]

See https://github.com/rails/rails/pull/35873#issuecomment-480333333
for reference

[Prathamesh Sonpatki, bogdanvlviv]

- It will return false in Rails 6.1 not 6.0. Also fixed the default
  value which is true for new applications.

- I feel `i18n_customize_full_messages` explains the meaning of the
  config better.
- Followup of https://github.com/rails/rails/pull/32956

A long-running `rails console --sandbox` could cause a database server
to become out-of-memory as it's holding on to changes that happen on the
database.

Given that it's common for Ruby on Rails application with huge
traffic to have separate write database and read database, we should
allow the developers to disable this sandbox option to prevent someone
from accidentally causing the Denial-of-Service on their server.