PG adapter deals with negative money values formatted with parenthesis.

Closes #11899.

Conflicts:
	activerecord/CHANGELOG.md

Backport of 27dc4fa.
:scissors:

[ci skip]
Review Action Pack CHANGELOG

[ci skip]
Review Active Record CHANGELOG

[ci skip]
Review Active Support CHANGELOG

[ci skip]
Remove gist link from the code

It is not good to include links in the code. These links can be in the
future outdated and nobody will upgrade they.

[ci skip]
Merge pull request #11997 from startupjockey/add_credits_AS

Adds Akshay Surve to Rails Guides credits list [ci skip]
fix typo in the credit section of the guides. [ci skip]
Soften wording about knowing other devs.

Many people don't, so point them to a place where they can meet
some.
Flesh out feedback portion of contributing guide.

I don't know of anyone that hangs out in #rails-contrib, and we should
also let people know that feedback can take some time.
Add note about features vs. bugs.

Sometimes people ask what makes a feature and what makes a bug, so
let's clarify that so we can show it to people later.
Warning on doc for assets under lib|vendor not precompiling [ci skip]
Merge pull request #12037 from SamSaffron/mem_alloc

Performance: Reduce memory allocations in Active Record
Review Action Mailer CHANGELONG

[ci skip]
Merge pull request #12038 from SamSaffron/memoize_decorate_cols

Perf: memoize serialized column list and time zone column list
Ensure all-caps nested consts marked as autoloaded

Previously, an autoloaded constant `HTML::SomeClass` would not be marked
as autoloaded by AS::Dependencies. This is because the
`#loadable_constants_for_path` method uses `String#camelize` on the
inferred file path, which in turn means that, unless otherwise directed,
AS::Dependencies watches for loaded constants in the `Html` namespace.

By passing the original qualified constant name to `#load_or_require`,
this inference step is avoided, and the new constant is picked up in the
correct namespace.

Conflicts:
	activesupport/CHANGELOG.md
Merge pull request #12015 from vipulnsward/add_dynamic_finders_to_upgrade

Add Finder API changes to upgrading guide [ci skip]
Merge pull request #11805 from jetthoughts/11803_update_move_forbidden_exception_description_before_show

[Getting Started Guide] Move Forbidden attributes description before show post section [ci skip]
Conflicts:
	guides/source/getting_started.md
Merge pull request #11768 from cloudspace/cache_template_loading

Only cache template digests if !config.cache_template_loading
Conflicts:
	actionview/CHANGELOG.md
Merge pull request #12048 from tjouan/app_generator-bin_perms-umask

Comply with current umask when generating new app