This fixes a bug when merging relations of different classes.

```
Given:
  Post.joins(:author).merge(Author.order(name: :desc)).to_sql

Before:
 SELECT "posts".* FROM "posts"
   INNER JOIN "authors" ON "authors"."id" = "posts"."author_id"
   ORDER BY "posts"."name" DESC

After:
 SELECT "posts".* FROM "posts"
   INNER JOIN "authors" ON "authors"."id" = "posts"."author_id"
   ORDER BY "authors"."name" DESC
```

This reverts commit fbcd46b1.

This is not needed anymore. See 72809654

This reverts commit 22f80ae5.

See
https://github.com/rails/rails/commit/22f80ae57b26907f662b7fd50a7270a6381e527e#commitcomment-4640676

Conflicts:
	activerecord/CHANGELOG.md

This is a follow-up to 3053fee9.

> The `master` branch should use the `master` branch.

this resolves the following error when running `bundle install`

```
ArgumentError: wrong number of arguments (2 for 1)
    /Users/senny/Projects/rails/.bundle/bundler/gems/arel-454a25f18c95/lib/arel/crud.rb:5:in `compile_update'
```

The build is still broken with lots of:

```
ArgumentError: wrong number of arguments (2 for 1)
    /Users/senny/Projects/rails/.bundle/bundler/gems/arel-454a25f18c95/lib/arel/crud.rb:5:in `compile_update'
```

[ci skip] `apropriate` => `appropriate`, spaces added

Fixed typos in "shallow routes" and "routing concerns" in routing.md [ci skip]

`skiping` => `skipping` [ci skip]

Grammatical tense correction: "There exists two" => "There exist two".
Plurality correction: "can be reused inside others resources" => "can be reused inside other resources".

added test cases to find notes in a file with .builder extension

Do not count query for all_constraints and all_tab_cols tested with Oracle

Address test_merging_where_relations failure by adding order

This will help identify these tasks exists, since they are easier to
setup things for running all AR tests.

Fix travis failures.

Drop unused param `should_be_quoted` to `PostgreSQLColumn#array_to_string`

[ci skip]updated documentation: added sass and less extensions

Build fix for ruby 1.9.3 syntax

Checks to see if the record contains the foreign_key to set the inverse automatically

Conflicts:
	activerecord/CHANGELOG.md

Track initializer's loaded event per file

In order to simplify profiling loading of initializers,
added instument for tracking load config initializer event from
`config/initializers`

avoiding iterations and calling of underscore on all elements of array

Test order dependency fixes

[ci skip] typo in ArgumentError in 4_0_release_notes.md

Fix bad test order dependency between LoadAllFixturesTest#test_all_there and FoxyFixturesTest#test_ignores_belongs_to_symbols_if_association_and_foreign_key_are_named_the_same

Fix bad test order dependency between test/cases/validations/i18n_generate_message_validation_test.rb and test/cases/validations/uniqueness_validation_test.rb

[ci skip] Update gem versions for 3.2 and 3.1. Also change some words.