CHANGELOG for 78d5d6f8

[ci skip]

It was pointed out by @giner that the CHANGELOG entry for https://github.com/rails/rails/commit/78d5d6f8688bb7c45ba9a3ef893682231130da3f
wasn't included. Here it is.

Fixes issues in test_mysql2

This commit inverts the precedence in ActionDispatch::Static so that
dynamic content will be served before static content. This is so that
precompiled assets do not inadvertently get included when running in
development mode - it should have no effect in production where static
files are usually handled by the web server.

Closes #6421

why is this a Time to start with?

This cleanup aims to fix a build failure:
https://travis-ci.org/rails/rails/jobs/3515951/#L482

Since travis always have both ENV vars set to "test", a test is failing
where it's expected to output the default env "development", but "test"
is the result due to RACK_ENV being set when we expect it to not be.

By cleaning this duplication we ensure that changing any of these env
variables will pick the right expected value.

To prevent future pull requests like #8435 add a comment about the
implementation of class_attribute using class_eval for performance.

[ci skip]

dump schema.rb without :version option

* joshsusser-master:
  style cleanup
  Add migration history to schema.rb dump
  Add metadata to schema_migrations

Conflicts:
	activerecord/CHANGELOG.md
	activerecord/lib/active_record/schema.rb

Revert turbolinks load order requirement

[ci skip]

Add ENV['RACK_ENV'] support to rake runner/console/server.

fix warning: possibly useless use of a constant in void context

Allow fragment cache to accept :if and :unless options.

Closes #5396

[Stephen Ausman + Fabrizio Regini]

Extract method refactoring.

Replace comments' non-breaking spaces with spaces [ci skip]

Sometimes, on Mac OS X, programmers accidentally press Option+Space
rather than just Space and don’t see the difference. The problem is
that Option+Space writes a non-breaking space (0XA0) rather than a
normal space (0x20).

This commit removes all the non-breaking spaces inadvertently
introduced in the comments of the code.

The other way it was not marking the text as italic, it was showing the
underlines as normal text.

Also fixes some code examples indentation and # => marks in Active Model
and Active Record guides.

[ci skip]

Fixing a spelling mistake [ci skip]

Fix #8414. Performance problem with postgresql adapter primary_key function.

Conflicts:
	guides/source/migrations.md

The release notes is changed to include only the major changes and point
to the changelogs for the complete list. This lets us talk more about the
features included in the upcoming release and make the guide more useful
and interesting than just a list of all changelogs.

This is still a WIP guide pending a lot of work.

[ci skip]

pg_namespace table isn't used.

This reverts commit 5ff59704.

Reason: Seems dubious and adds less value.

[ci skip]