s/Dont'/Don't/
create_table + transactional_fixtures = :bomb:
Use the method for determining attribute methods rather than duplicating

I've been trying to reduce the number of places that care about
`attributes`, and its existence. We have a method for this check, let's
use it instead.
Merge pull request #16505 from sgrif/sg-attribute-internals

Use the method for determining attribute methods rather than duplicating
prefer `has_attribute?` over `attributes.key?`.

Follow up to the discussion on #16505.
fix typo in method name (broken build :sweat:)
Fixed link for in_place_editor [ci skip]

closes #16512
Point to rubygems instead of Rails GitHub. [ci skip]

The rails repository is not the official plugin anymore
Implement `==` on `Type::Value` and `Attribute`

This was a small self contained piece of the refactoring that I am
working on, which required these objects to be comparable.
Use *_transaction methods in TransactionManager

Use `commit_transaction`/`rollback_transaction` on
`within_new_transaction` method, so they make sure they `pop` the
transaction from the stack before calling the methods `commit`/`rollback`.
Fix regression on after_commit in nested transactions.

after_commit should not run in nested transactions, however they should
run once the outermost transaction gets committed. This patch fixes the
problem copying the records from the Savepoint to its parent. So the
RealTransaction will have all records that needs to run callbacks on it.

[fixes #16425]
Merge pull request #16435 from arthurnn/after_commit_run_on_top_level_trans_master

Fix regression on after_commit in nested transactions. (master)
Unused ivar in a test suite
Avoid polluting String class globally in a test case
Avoid mutating the constants in a test case
[ci skip] re-worded section on CookieStore to make it more readable.
Merge pull request #16523 from tomkadwill/cookie_store_rewording

[ci skip] re-worded section on CookieStore to make it more readable.
Merge pull request #16517 from sgrif/sg-comparable-attributes

Implement `==` on `Type::Value` and `Attribute`
Implement `_was` and `changes` for in-place mutations of AR attributes
Don't expose these new APIs yet (added in 877ea78 / #16189)

WARNING: don't use them! They might change or go away between future beta/RC/
patch releases!

Also added a CHANGELOG entry for this.