- Rails 5 will return 204 No Content by default for controller actions
  which do not have a template or do not specify how to render.
- The "Getting started" guide needs to be updated for this.

This is an slight refactoring/improved version of #25586.

add missing things to release notes [ci skip]

Add following.

* https://github.com/rails/rails/commit/05934d24aff62d66fc62621aa38dae6456e276be
* https://github.com/rails/rails/commit/38d2bf5fd1f3e014f2397898d371c339baa627b1
* https://github.com/rails/rails/pull/25469

Add API Apps to release notes

Pass over Upgrading guide

It's useful to have a link to the release notes in the upgrade guide for
a clearer view of what changed in Rails.

Make release notes about legacy `mysql` adapter clearer.

Adds missing upgrade items to the upgrade guides for Rails 5. Fixes some
typos and whitespace as well.

Add documentation about Action Cable npm package

[ci skip] Update formatting in ActionView::Base documentation

[ci skip] Fix grammar & add link in PolymorphicRoutes

Do not inspect array of over 10 elements

Do not specal case inspecting associated arrays of over 10 elements, preventing infinite looping in some cases.

Right now with this middleware we are likely always connected, but I'm
hoping to change that soon. This is an easy change to pull out on its
own.

This method appears to have been partially used in connection pool
caching, but it was introduced without much reasoning or any tests. One
edge case test was added later on, but it was focused on implementation
details. This method is no longer used outside of tests, and as such is
removed.

update description of `test_order` [ci skip]

Follow up to 5f777e4b

Add coverage for #25529

Fix `Type::Date#serialize` to return a date object correctly

- Renamed test to be more descriptive

Fix setting route's to in a scope

Signed-off-by: NJeremy Daer <jeremydaer@gmail.com>

Fixes #25488
97d7dc48 introduced a regression that resulted in ArgumentError when to
was in options of the scope and not of particular route.

Require our dependency and forgo the core ext version.

This reverts commit acf0bb3f, reversing
changes made to c5b766a9.

Travis can only build a commit it can clone; without any clone depth,
all branch builds error as soon as there's a newer commit present.

Removes littering `freeze` calls with Ruby 2.3's magic comment.

Bring Boolean Attributes list for AV Tags helper upto speed with current spec

Expand list of void elements to match spec

Freeze string for default content for tag_strings, which later goes on to build a new one

This is based on https://github.com/kangax/html-minifier/blob/6b2d4536d82819143b468b41a89c700b6c61631f/src/htmlminifier.js#L197 and
spec from https://www.w3.org/TR/html51/single-page.html.

Couple of other changes to tests due to support update:
- autobuffer has been dropped in favour of preload attribute, ref: https://msdn.microsoft.com/en-us/library/ff974743(v=vs.85).aspx
- pubdate attribute has been dropped from spec, ref:  https://www.w3.org/html/wg/tracker/issues/185

Freeze string for default content for tag_strings, which later goes on to create new content. This should also be inline with content being passed should not be mutable