Create 4.2 release notes guide scaffold [ci skip]

Point to future 4-2-stable branch for detailed changes. [ci skip]

Sync Active Support changelogs with release notes [ci skip]

4.2 Release Notes is a work in progress [ci skip]

Assorted fixes for AS release notes [ci skip]

* `Hash#deep_transform_keys` has already been backported
* Mentioning `ActiveSupport::SafeBuffer#prepend` in the "Deprecations" section would be enough
* Fix syntax in `Kernel#concern` example

Sync AS release notes with the latest commits [ci skip]

Synced 4.2 release notes with commits in railties [ci skip]

Sync AP Deprecations and Notable changes from CHANGELOG [ci skip]

Removed 4.2 release notes from the index [ci skip]

This deprecation was reverted in 489a8f2 [ci skip]

Synced Active Record changelogs for 4.2 release notes [ci skip]

Synced Active Model changelog with the release notes [ci skip]

Added cc26b6b as a 'Removal' item in AP release notes [ci skip]

Use 'character' instead of 'symbol' to avoid confusion [ci skip]

Edit pass on 4.2 release notes [ci skip]

:memo: :lipstick: Use `.xyz` and `#xyz` appropiately [ci skip]
First pass at Rails 4.2 release notes [ci skip]
Merge pull request #15306 from rails/4-2-release_notes

Rails 4.2 release notes [ci skip]
Revert code changes at "Copy edits and code font wrap for Active Record [ci skip]"

This partially reverts commit 1a203d5e07f639332880099fab610b886b1742fc.

Reason: It was committed by accident
Reorder test which does not represent real world usage

We don't generally modify our classes at runtime like this. Let's create
the instance after the class is created. Original commit doesn't imply
that this was intentional behavior.
Reword PreparedStatementInvalid example, and use values instead of
variables [ci skip]
Thanks to @matthewd for the excellent feedback! :heart:
s/variable supplied/value supplied [ci skip]
Merge pull request #15696 from sgrif/sg-bad-test

Reorder test which does not represent real world usage
Remove unused `method_missing` definition

We always define attribute methods in the constructor or in `init_with`.