additional note about routes in functional tests for engines [ci skip]
Improve Contributing to Rails Guide

Logically group the content, so it makes more sense if someone tries to read from start of page to end of page. [ci skip]
Add documentation for Thread#freeze
Instead boat load of libraries, simply say StdLib
Use path where extensions are defined, not used

For consistency with all other documentation, point to where these core
extensions are defined, not where the example code comes from.

[ci skip]
Document LoadError core extensions

[ci skip]
Fix a few grammar issues. [ci skip]
Correct docs as singlton true is not returned here

[ci skip]
The comparison between `Relation` and `CollectionProxy` should be consistent.

Example:

    author.posts == Post.where(author_id: author.id)
    # => true
      Post.where(author_id: author.id) == author.posts
    # => true

Fixes #13506
Make the comparison between 'Relation' and 'AssociationRelation'
consistent.
Ensure that the comparison between 'CollectionProxy' and 'AssociationRelation' is consistent.
CollectionHelpers now accepts a readonly option
Move tests for deep_dup and duplicable to object directory
Add a changelog entry for #14546 [ci skip]
Remove surplus period from assertion messages
Update documentation to use Rails.application instead

References to ``AppName::Application` removed in favour of ``Rails.application``
as generated with a new rails 4.1 app.

[ci skip]
Merge pull request #14727 from robin850/patch-17

Add a changelog entry for #14546 [ci skip]
Merge pull request #14718 from mcmorgan/update-documentation-to-match-generated-config

Update documentation to use Rails.application instead
Merge pull request #14722 from maurogeorge/mg-readonly-collection

CollectionHelpers now accepts a readonly option
Fix spelling errors and grammar issues

Including replacing a few "smart quotes" with regular quotes (' and "),
for consistency.
[ci skip]