Currently, `app:update` generates all contents regardless of the
component using in application.

For example, even if not using Action Cable, `app:update` will generate
a contents related to Action Cable. This is a little inconvenient.
This PR checks the existence of the component and does not generate
unnecessary contents.
Can not check all options in this way. However, it will be able to
prevent the generation of unnecessary files.

In encrypted secrets, the tmp file is used as a fixed file
(`secrets.yml.enc` under the tmp directory).
And that tmp file will be removed after process.

Therefore, if edit secrets at the same time with multiple applications,
the tmp file was conflicting.

In order to avoid the above issue, added pid to tmp file.

Abstract boolean serialization has been using 't' and 'f', with MySQL
overriding that to use 1 and 0.

This has the advantage that SQLite natively recognizes 1 and 0 as true
and false, but does not natively recognize 't' and 'f'.

This change in serialization requires a migration of stored boolean data
for SQLite databases, so it's implemented behind a configuration flag
whose default false value is deprecated. The flag itself can be
deprecated in a future version of Rails.  While loaded models will give
the correct result for boolean columns without migrating old data,
where() clauses will interact incorrectly with old data.

While working in this area, also change the abstract adapter to use
`"TRUE"` and `"FALSE"` as quoted values and `true` and `false` for
unquoted.  These are supported by PostreSQL, and MySQL remains
overriden.

Rather than protecting from forgery in the generated
ApplicationController, add it to ActionController::Base by config. This
configuration defaults to false to support older versions which have
removed it from their ApplicationController, but is set to true for
Rails 5.2.

By making the Rails minitest behave like a standard minitest plugin
we're much more likely to not break when people use other minitest
plugins. Like minitest-focus and pride.

To do this, we need to behave like minitest: require files up front
and then perform the plugin behavior via the at_exit hook.
This also saves us a fair bit of wrangling with test file loading.

Finally, since the environment and warnings options have to be applied
as early as possible, and since minitest loads plugins at_exit, they
have to be moved to the test command.

* Don't expect the root method.

It's likely this worked because we eagerly loaded the Rails minitest plugin
and that somehow defined a root method on `Rails`.

* Assign a backtrace to failed exceptions.

Otherwise Minitest pukes when attempting to filter the backtrace (which
Rails' backtrace cleaner then removes).

Means the exception message test has to be revised too.

This is likely caused by the rails minitest plugin now being loaded for
these tests and assigning a default backtrace cleaner.

Currently the environment file is not loaded in `dbconsole` command.
Therefore, for example, if use encrypted secrets values in database.yml,
`read_encrypted_secrets` will not be true, so the value can not be
used correctly.

Fixes #29717

Until Rails 5.1.1 secrets was treated as binary inside Rails.
https://github.com/rails/rails/blob/v5.1.1/railties/lib/rails/secrets.rb#L59
https://github.com/rails/rails/blob/v5.1.1/railties/lib/rails/secrets.rb#L63

However, it is treated as String in Rails 5.1.2(changed by 157db872).
https://github.com/rails/rails/blob/v5.1.2/railties/lib/rails/secrets.rb#L104
https://github.com/rails/rails/blob/v5.1.2/railties/lib/rails/secrets.rb#L108

As a result, when upgrading from Rails 5.1.1 to 5.1.2, to write the value
treated as binary using `File.write`, causing an error.

In order to avoid `UndefinedConversionError`, fixed it to treat it as
binary like 5.1.1.
Fixes #29696

Currently, if open a file with `secrets:edit` command, `secrets.yml.enc`
will be changed even if its contents do not change.

Therefore, even if only want to check secrets, the difference will come
out. This is a little inconvenient.

As a fix to the above problem, when content does not change,
`secrets.yml.ecn` is fixed so that it is not changed.

When secrets confirmed with the `secrets:edit` command, `secrets.yml.enc`
will change without updating the secrets.

Therefore, even if only want to check secrets, the difference will come
out. This is a little inconvenient.

In order to solve this problem, added the `secrets:show` command.
If just want to check secrets, no difference will occur use this command.

Now that the parameters configurations are only loaded when
ActionController::Base is we need to foce them to load in our tests. In
an application this is not needed since every request already load the
controllers.

These tests relied on `ActionController::Parameters` being configured as
part of the boot process; since that now happens lazily we need to force
`ActionController::Base` to load so that we can test the behaviour.

The new tests added here ensure that `ActionController::Parameters` can
be configured from an initializer, which was broken until recently.

It is covered by following assertion.

This reverts commit 3420a145, reversing
changes made to afb66a5a.

If system test fails, it creates screenshot under `tmp/screenshots`.
https://github.com/rails/rails/blob/34fe2a4fc778d18b7fe6bdf3629c1481bee789b9/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb#L45

But currently, screenshot files is not cleared by `tmp:clear` task.
This patch make clears screenshot files with `tmp:clear` task as well
as other tmp files.

The `capify` command has been removed by Capistrano 3 and became to
`cap install`.
Therefore, the `capify!` method has no meaning in Capistrano 3.
I think that should deprecate.

Ref: https://github.com/capistrano/capistrano/commit/492793916acf32ffe1604daec6fd4892c8935018

- [Rails <= 5.0](https://github.com/rails/rails/blob/5-0-stable/railties/lib/rails/commands/test.rb#L6) used to add the `<app_root>/test` as a string; this behaviour changed in rails 5.1, it's appending a `Pathname` object

The fact that the names need to be globally unique was not obvious to me, so I
thought it'd be worth documenting. This not being clear was the cause of both
ctran/annotate_models#468 and instructure/outrigger#1.

[ci skip]

We don't provide exactly the same experience as IRB does, so let's not
advertize it like that. We can say that it's an interactive console,
without further references. I have also followed byebug's comment and
changed the calling `console` part. Hopefully, this can hint that the
invocation is not view specific and you can use it like the debugger
statement.

[ci skip]

- Introduce a method to select default cipher, and maintain backward compatibility

Fix the mistake of not using Ruby's ENV hash from the get go and get
windows support.

We don't get any benefit from it at all.