Fix digest ETAG test.

After
https://github.com/rack/rack/commit/12528d4567d8e6c1c7e9422fee6cd8b43c4389bf
ETag will include a `W/` before the digest.

Moved #create! method from Validations to Persistence module

Also keep the hook as other tools may rely on it,
we just don't do anything by default on Rails.

The method has been removed in 09206716
(PR #16074), but the delegation was apparently missed, and one instance
of the method was added back with the addition of OID::Xml in
336be2bd (PR #16072), so we can safely
rm both.

we know that this call only wants the path returned, so lets call a
method that returns the path.

Don't delegate Reflection#chain to ThroughAssociation

We shouldn't be delegating chain to ThroughAssociation since the
only place that needs to call it is `target_scope`. Instead we
can call `reflecion.chain`.

Update itself.rb [ci skip]

Guides: Add definition of `config.assets.manifest` option to configuring.md

Ruby 2.2 will include Kernel#itself so we don't need to define again.

See
https://github.com/ruby/ruby/commit/0a0160d6b659f6131a525fe1579e7c463d4c197e

Fix typo [ci skip]

Fixed broken test.

Thanks Stephen Richards for reporting.

Fix type casting to Decimal from Float with large precision

Conflicts:
	activerecord/CHANGELOG.md

Using no_result_var in Journey's parser generator

Previously the generated parser had an intermediate local variable
`result` that really useful if you're building up a stateful object but
Journey always discards the result argument to the reduce functions.

This produces a simpler parser for anybody who actually wants to read
the thing.

Sadly, there's no real performance speedup with this change.

Change the production log level default from :info to :debug. All production apps I have ever worked with has done this. Let us reflect that default. You often want those SQL quieries to be able to debug issues in production

Generating stubs for helper tests is overly specific. Most helpers should simply be tested as part of the view thats using them. If you need something beyond that, you can add a test yourself for them

[ci skip] add tip for uglifier in execjs error

[ci skip] Remove "Machinist" from testing guide

[doc] updating documented parameter for build_constraint

Updates documentation in line with changes made in
743b6750

Fixes small error in ActiveRecord::Reflection docs