We should call `scope.order!` and set `scope.reordering_value` to `true` if :reordering values are specified

Fixes #21886

This solves the following issue:

```
$ bin/test
Using sqlite3
/Users/senny/Projects/rails/activerecord/test/cases/adapters/mysql2/sp_test.rb:16:in `<class:Mysql2StoredProcedureTest>': undefined method `version' for #<ActiveRecord::ConnectionAdapters::SQLite3Adapter:0x007f8bab4b5b70> (NoMethodError)
	from /Users/senny/Projects/rails/activerecord/test/cases/adapters/mysql2/sp_test.rb:5:in `<top (required)>'
	from /Users/senny/Projects/rails/activesupport/lib/active_support/dependencies.rb:302:in `require'
	from /Users/senny/Projects/rails/activesupport/lib/active_support/dependencies.rb:302:in `block in require'
	from /Users/senny/Projects/rails/activesupport/lib/active_support/dependencies.rb:268:in `load_dependency'
	from /Users/senny/Projects/rails/activesupport/lib/active_support/dependencies.rb:302:in `require'
	from /Users/senny/Projects/rails/railties/lib/rails/test_unit/test_requirer.rb:11:in `block in require_files'
	from /Users/senny/Projects/rails/railties/lib/rails/test_unit/test_requirer.rb:10:in `each'
	from /Users/senny/Projects/rails/railties/lib/rails/test_unit/test_requirer.rb:10:in `require_files'
	from /Users/senny/Projects/rails/railties/lib/rails/test_unit/minitest_plugin.rb:69:in `plugin_rails_init'
	from /Users/senny/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.3.3/lib/minitest.rb:73:in `block in init_plugins'
	from /Users/senny/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.3.3/lib/minitest.rb:71:in `each'
	from /Users/senny/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.3.3/lib/minitest.rb:71:in `init_plugins'
	from /Users/senny/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.3.3/lib/minitest.rb:122:in `run'
	from bin/test:19:in `<main>'
```

Use #distinct instead of #uniq in the guides

* #uniq is an alias of #distinct
* #uniq will be deprecated, see: rails/rails@adfab2dcf4003ca564d78d4425566dd2d9cd8b4f

It's already represented in the key name. Demonstrate with a test.

Also test that the default isn't output.

Allow rake:stats to account for rake tasks

Add support for bidirectional destroy dependencies

Remove required `sdoc` from Rakefile

[ci skip] Add `:binds` to a list of paramaters of `sql.active_record`

specify deprecated waring, follow the standard conventions

`skip_filter`, `skip_action_callback` may both are deprecated in Rails 5.1 so waring msg should be specific.

For ActionController::Base we write the cookies in a middleware if it
was not yet committed no matter if the response was committed or not. [1]

For ActionController::Live we write the cookies before the response is
committed. [2]

We already mimic ActionController::Live in
ActionController::TestCase but we don't mimic the ActionController::Base
behavior because we were checking if the response was committed before
writing the cookies.

Now we are matching the behavior of the middleware and writing the
cookies if it was not written before.

[1]: https://github.com/rails/rails/blob/80c6b901d4d87cee610ab0a438ff6e3c6bf118d1/actionpack/lib/action_dispatch/middleware/cookies.rb#L599-L604
[2]: https://github.com/rails/rails/blob/80c6b901d4d87cee610ab0a438ff6e3c6bf118d1/actionpack/lib/action_controller/metal/live.rb#L218-L223

This is leftover from when `render nothing: true` rendered blank string.

Fix Typo in EagerLoadPolymorphicError [ci skip]

Includes HABTM returns correct size now

fix typo in `db:purge` description [ci skip]

[ci skip] Aline code examples in AR changelog

raise `ArgumentError` when `SECRET_KEY_BASE` is an integer

If `SECRET_KEY_BASE` or other `secret` gets passed as other then string
we need to raise `ArgumentError` to know that it's a wrong argument.

Closes #22072

This reverts commit 60c97012, reversing
changes made to 6a25202d.

Reason: Broken build

Fix InheritanceTest#test_scope_inherited_properly implementation bugs

This triggers the JoinDependency work to reflect on the associations
and trigger an error as follows:

  ActiveRecord::ConfigurationError: Association named 'account' was
  not found on Company; perhaps you misspelled it?

Fix Company.of_first_firm joins association name

Should be `Company.joins(:accounts)` not `Company.joins(:account)`.

Do the same for Client.of_first_firm

Errors can be indexed with nested attributes

Close #8638

Edits default `config/boot.rb` to match what's generated by Rails 4.2.

Explicitly exit with status "1" for create and drop failures

Make `Module#redefine_method` to keep method visibility

This is required inside `api/task`

Before this commit `Module#redefine_method` always changes
visibility of redefined method to `public`.
This commit changes behavior of Module#redefine_method` to
keep method visibility.

Do not omit parentheses [ci skip]

Tweaked wording used in some tests.