`BigDecimal.new` has been deprecated in BigDecimal 1.3.3
 which will be a default for Ruby 2.5.

Refer
https://github.com/ruby/bigdecimal/commit/533737338db915b00dc7168c3602e4b462b23503

* This commit has been made as follows:

```
cd rails
git grep -l BigDecimal.new | grep -v guides/source/5_0_release_notes.md | grep -v activesupport/test/xml_mini_test.rb | xargs sed -i -e "s/BigDecimal.new/BigDecimal/g"
```
- `activesupport/test/xml_mini_test.rb`
Editmanually to remove `.new` and `::`

- guides/source/5_0_release_notes.md
This is a Rails 5.0 release notes.

* The `DEFAULT_ERROR_HANDLER` constant in
  `ActiveSupport::Cache::RedisCacheStore` contained references
  to an undefined argument `e`, which is supposed to refer
  to the `exception` parameter.
* Update the default error handler proc to correctly reference
  the `exception` parameter.

Provide instant feedback when booting Rails

Suppress `warning: BigDecimal.new is deprecated` in Active Model

Address `warning: instance variable @hash_digest_class not initialized`

Suppress expected exceptions by `report_on_exception` = `false` in mysql2 test

Follow up #31428 to address similar exceptions with mysql2 adapter

`BigDecimal.new` has been deprecated in BigDecimal 1.3.3
 which will be a default for Ruby 2.5.

Refer ruby/bigdecimal@5337373

* This commit has been made as follows:

```ruby
$ cd activemodel/
$ git grep -l BigDecimal.new | grep \.rb | xargs sed -i -e "s/BigDecimal.new/BigDecimal/g"
```

* This commit has been tested with these Ruby versions:

```
ruby 2.5.0dev (2017-12-15 trunk 61262) [x86_64-linux]
ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-linux]
ruby 2.3.5p376 (2017-09-14 revision 59905) [x86_64-linux]
ruby 2.2.8p477 (2017-09-14 revision 59906) [x86_64-linux]
```

```ruby
/path/to/rails/activesupport/lib/active_support/digest.rb:7:
warning: instance variable @hash_digest_class not initialized
``

Initial support for running Rails on FIPS-certified systems

Log the original call site for an ActiveRecord query

Follow up of #31432.

I've noticed during pair/mob programming sessions with peers that
despite the speed boosts provided by Bootsnap and Spring, there is a
noticeable latency between firing a bin/rails server command and any
feedback being provided to the console. Depending on the size of the
application this lack of feedback can make it seem like something is
wrong when Rails is simply busy initializing.

This change may seem gratuitous but by just printing one line to STDOUT
we're giving a clear signal to the Rails user that their command has
been received and that Rails is indeed booting. It almost imperciptibly
makes Rails feel more responsive.

Sure the code doesn't look very fancy but there's no other appropriate
place I could think of putting it than boot.rb.

Compare these two GIFs of booting without and with this change:

Before:
![Without Boot Feedback](https://user-images.githubusercontent.com/65950/33964140-721041fc-e025-11e7-9b25-9d839ce92977.gif)

After:
![With Boot Feedback](https://user-images.githubusercontent.com/65950/33964151-79e12f86-e025-11e7-93e9-7a75c70d408f.gif)

This new ActiveRecord configuration option allows you to easily
pinpoint what line of application code is triggering SQL queries in the
development log by appending below each SQL statement log the line of
Ruby code that triggered it.

It’s useful with N+1 issues, and to locate stray queries.

By default this new option ignores Rails and Ruby code in order to
surface only callers from your application Ruby code or your gems.

It is enabled on newly generated Rails 5.2 applications and can be
enabled on existing Rails applications:

```ruby
Rails.application.configure do
  # ...
  config.active_record.verbose_query_logs = true
end
```

The `rails app:upgrade` task will also add it to
`config/development.rb`.

This feature purposely avoids coupling with
ActiveSupport::BacktraceCleaner since ActiveRecord can be used without
ActiveRecord. This decision can be reverted in the future to allow more
configurable backtraces (the exclusion of gem callers for example).

The v4.3.1 has already released that includes Redis 4.0 support.
https://github.com/resque/resque-scheduler/blob/master/CHANGELOG.md#431---2017-11-20

Preserve original method visibility when deprecating a method

Suppress `warning: BigDecimal.new is deprecated` in activerecord

`BigDecimal.new` has been deprecated in BigDecimal 1.3.3
 which will be a default for Ruby 2.5.

Refer https://github.com/ruby/bigdecimal/commit/533737338db915b00dc7168c3602e4b462b23503

```
$ cd rails/activerecord/
$ git grep -l BigDecimal.new | grep \.rb | xargs sed -i -e "s/BigDecimal.new/BigDecimal/g"
```

- Changes made only to Active Record. Will apply the same change to
other module once this commit is merged.

- The following deprecation has not been addressed because it has been
reported at `ActiveRecord::Result.new`. `ActiveRecord::Result.ancestors`
did not show `BigDecimal`.

* Not addressed

```ruby
/path/to/rails/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb:34:
warning: BigDecimal.new is deprecated
```

* database_statements.rb:34

```ruby
ActiveRecord::Result.new(result.fields, result.to_a) if result
```

* ActiveRecord::Result.ancestors

```ruby
[ActiveRecord::Result,
 Enumerable,
 ActiveSupport::ToJsonWithActiveSupportEncoder,
 Object,
 Metaclass::ObjectMethods,
 Mocha::ObjectMethods,
 PP::ObjectMixin,
 ActiveSupport::Dependencies::Loadable,
 ActiveSupport::Tryable,
 JSON::Ext::Generator::GeneratorMethods::Object,
 Kernel,
 BasicObject]
```

This commit has been tested with these Ruby and BigDecimal versions

- ruby 2.5 and bigdecimal 1.3.3

```
$ ruby -v
ruby 2.5.0dev (2017-12-14 trunk 61217) [x86_64-linux]
$ gem list |grep bigdecimal
bigdecimal (default: 1.3.3, default: 1.3.2)
```

- ruby 2.4 and bigdecimal 1.3.0

```
$ ruby -v
ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-linux-gnu]
$ gem list |grep bigdecimal
bigdecimal (default: 1.3.0)
```

- ruby 2.3 and bigdecimal 1.2.8

```
$ ruby -v
ruby 2.3.5p376 (2017-09-14 revision 59905) [x86_64-linux]
$ gem list |grep -i bigdecimal
bigdecimal (1.2.8)
```

- ruby 2.2 and bigdecimal 1.2.6
```
$ ruby -v
ruby 2.2.8p477 (2017-09-14 revision 59906) [x86_64-linux]
$ gem list |grep bigdecimal
bigdecimal (1.2.6)
```

This commit fixes `deprecate` so that it preserves method visibility (like it
did previously when it was utilizing `alias_method_chain`).

When Module#prepend replaced alias_method_chain in a982a42d it caused deprecated
methods to always become public.

`alias_method_chain` had this bit of code:
https://github.com/rails/rails/blob/v5.0.6/activesupport/lib/active_support/core_ext/module/aliasing.rb#L40-L47
which preserved method visibility.

Without this fix, a workaround would be:

```ruby
class C8
  private

  def new_method
  end

  def old_method
  end
  deprecate :old_method, :new_method
  # workaround:
  instance_method(:old_method).owner.send(:private, :old_method)
end
```

Because the visibility needs to be fixed on the Module prepended by
MethodWrapper.

[ci skip] Add a space to comment in SidekiqAdapter

* I think it's better to have a leading space after the `#`
  denoting the start of the comment.

Expose Active Storage routes

Suppress expected exceptions by `report_on_exception` = `false`

* Ruby 2.4 introduces `report_on_exception` to control if it reports exceptions in thread,
this default value has been `false` in Ruby 2.4.

Refer https://www.ruby-lang.org/en/news/2016/11/09/ruby-2-4-0-preview3-released/

* Ruby 2.5 changes `report_on_exception` default value to `true`
since this commit https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?revision=61183&view=revision

This pull request suppresses expected exceptions by setting `report_on_exception` = `false`
it also supports Ruby 2.3 which does not have`report_on_exception`.

Make it same title in index and page [ci skip]

Fix active_storage installation failure when in engine

We need to pass scope attributes to `klass.new` to detect subclass.
Otherwise `subclass_from_attributes` can't detect subclass which is had
in scope attributes.

Fixes #18062.
Closes #18227.
Closes #30720.

Optimizing information_schema query for `foreign_keys`

Fix protected environments with symbols

Use CONSTRAINT_SCHEMA key for information_schema.referential_constraints.
See https://dev.mysql.com/doc/refman/5.7/en/information-schema-optimization.html.

```
> EXPLAIN SELECT fk.referenced_table_name AS 'to_table', fk.referenced_column_name AS 'primary_key', fk.column_name AS 'column', fk.constraint_name AS 'name', rc.update_rule AS 'on_update', rc.delete_rule AS 'on_delete' FROM information_schema.referential_constraints rc JOIN information_schema.key_column_usage fk USING (constraint_schema, constraint_name) WHERE fk.referenced_column_name IS NOT NULL AND fk.table_schema = 'activerecord_unittest' AND fk.table_name = 'fk_test_has_pk' AND rc.constraint_schema = 'activerecord_unittest' AND rc.table_name = 'fk_test_has_pk'\G
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: rc
   partitions: NULL
         type: ALL
possible_keys: NULL
          key: CONSTRAINT_SCHEMA,TABLE_NAME
      key_len: NULL
          ref: NULL
         rows: NULL
     filtered: NULL
        Extra: Using where; Open_full_table; Scanned 0 databases
*************************** 2. row ***************************
           id: 1
  select_type: SIMPLE
        table: fk
   partitions: NULL
         type: ALL
possible_keys: NULL
          key: TABLE_SCHEMA,TABLE_NAME
      key_len: NULL
          ref: NULL
         rows: NULL
     filtered: NULL
        Extra: Using where; Open_full_table; Scanned 0 databases; Using join buffer (Block Nested Loop)
2 rows in set, 1 warning (0.00 sec)
```

  - Add mention about `config.active_record.internal_metadata_table_name`
  - Add mention about `config.active_record.protected_environments`

  These changes prevent ignoring environments name of which is a `Symbol`
  ```
  config.active_record.protected_environments = ['staging', :production]
  ```

Currently, sanitize methods are private. So need `send` to use from
outside class.
However, sometimes want to use sanitize methods from outside Class when
want to generate SQL including multiple tables like search.
In order to avoid using `send` in such a case, changed methods to public.

Merge pull request #31405 from bogdanvlviv/fix-conflicts-counter_cache-with-touch-by-optimistic_locking

Fix conflicts `counter_cache` with `touch: true` by optimistic locking.

Fix doc typo [ci skip]