From the Pull Request #6461

This reverts commit 724d6fa6.

Reason: This is already documented in another section, albeit without
the arguments examples. Let's add them in another commit in the
appropriate sections

[ci skip]

Add a railtie's changelog entry about runner hook.

Some of the warnings removed from "railties"

Fix human attribute_name to handle deeply nested attributes

True, False, and Nil should be represented in as_json as themselves.

[Guides] refactor rakefile to have a :guides namespace and a task that shows help

(Try again) Fix #5847 and #4045.

JRuby return different Array for module contents.

Test was failing against JRuby. 

It loads like [Constant3 Constant1]

Exceptions like Interrupt & NoMemoryError should not be rescued in tests.

update Gemfile template to 1.9 hash syntax