Revert "Object#in? also accepts multiple parameters"

This reverts commit ebf69ab1636df74c76332c53bcd3d8494fb91b45.

`in?` must not take multiple parameters because its behavior would be
ambiguous:

    # Test if "B" is included in a list of names with `"B".in?(*names)`:
    names = ["BMorearty"]
    "B".in?(*names)   # => true

    names = ["BMorearty","rubyduo"]
    "B".in?(*names)   # => false

Conflicts:
	activesupport/lib/active_support/core_ext/object/inclusion.rb
	activesupport/test/core_ext/object/inclusion_test.rb
Revert the guide after removing varargs from `in?`.
Fix failing AP test
Merge pull request #10394 from BMorearty/remove-varargs-from-in

Remove varargs from `Object#in?`
Make railties version match RAILS_VERSION
Merge pull request #10405 from rubys/410-beta

Make railties version match RAILS_VERSION
allow override of uuid_generate_v4() default by passing default: nil

without this, it's not possible to use UUID primary keys without uuid-ossp installed and activated
Merge pull request #10404 from chadmoone/fix-pg-uuid-default

Allow override of PostgreSQL UUID primary key default
Handle aliased attributes in ActiveRecord::Relation.

When using symbol keys, ActiveRecord will now translate aliased attribute names to the actual column name used in the database:

With the model

  class Topic
    alias_attribute :heading, :title
  end

The call

  Topic.where(heading: 'The First Topic')

should yield the same result as

  Topic.where(title: 'The First Topic')

This also applies to ActiveRecord::Relation::Calculations calls such as `Model.sum(:aliased)` and `Model.pluck(:aliased)`.

This will not work with SQL fragment strings like `Model.sum('DISTINCT aliased')`.

Github #7839

*Godfrey Chan*
use constant for encoding
Merge pull request #10407 from NARKOZ/encoding-constant

Use constant for encoding
Improve docs for postgresql with uuid primary keys [ci skip]

Introduced in 09ac1776abc0d3482f491f2d49f47bcb3d9a4ad7.
Merge pull request #7839 from chancancode/handle_aliased_attributes_in_ar_relation

Handle aliased attributes in AR::Relation
Convert ActiveModel to 1.9 hash syntax.

I also attempted to fix other styleguide violations such as
{ a: :b } over {a: :b} and foo(b: 'bar') over foo( b: 'bar' ).
Merge pull request #10408 from patricksrobertson/convert_activemodel_to_new_hash_syntax

Convert ActiveModel to 1.9 hash syntax.
Extract tests code out from AR's base_test.rb to integration_test.rb

`AR::Base#to_param` and `AR::Base#cache_key` is defined at
active_record/integration.rb, so tests for those methods should be at
integration_test.rb
Merge pull request #10396 from tkhr/extract-test-code-from-base_test.rb

Extract tests code out from AR's base_test.rb to integration_test.rb
Fix failures in AS with minitest 4.7.4
Remove not used module from initializable test