With ActiveRecord::Properties, we now have a reasonable path for users
to continue to keep this behavior if they want it. This is an edge case
that has added a lot of complexity to the code base.

Add a public API to allow users to specify column types

See also:
https://github.com/rails/rails/commit/3a297f8db75b172882bb3c2f9440d0c7365b8b11#commitcomment-6451708

As a result of all of the refactoring that's been done, it's now
possible for us to define a public API to allow users to specify
behavior. This is an initial implementation so that I can work off of it
in smaller pieces for additional features/refactorings.

The current behavior will continue to stay the same, though I'd like to
refactor towards the automatic schema detection being built off of this
API, and add the ability to opt out of automatic schema detection.

Use cases:

- We can deprecate a lot of the edge cases around types, now that there
  is an alternate path for users who wish to maintain the same behavior.
- I intend to refactor serialized columns to be built on top of this
  API.
- Gem and library maintainers are able to interact with `ActiveRecord`
  at a slightly lower level in a more stable way.
- Interesting ability to reverse the work flow of adding to the schema.
  Model can become the single source of truth for the structure. We can
  compare that to what the database says the schema is, diff them, and
  generate a migration.

Allow empty arrays in where predicates

Extract types which don't require additional typecasting to a method

Database specific adapters shouldn't need to override `type_cast` to
define types which are already in an acceptable state.

[ci skip] Add benchmark your code section to contributing to ruby on rails guide.

I have seen many times that maintainers want people to use this gem to give
a benchmark report. It would be nice to add it and refer to it later.

Refactor reflections

Now the internal reflections will hold a reference to its public
representation, so when the outside world calls `Account.reflection` we
can build a list of public reflections.

Refactor the handling of arrays in where predicates

Simplifies the code slightly, isolates non-nil non-range values into a
single array, which will make it easier to do things like apply type
casting to them in the future.

Docs: Rename Posts to Articles in Guides' Getting Started App

correct documentation for asset_path and image_path [ci skip]

Skip individual tests upon Dalli::RingError

correct docs for audio_tag and video_tag [ci skip]

Unlike the outer `rescue`, this one is much more precise about what we
want to handle: a connection failure (`Dalli::RingError`) is not
relevant to what we're testing here. But other Dalli errors may well be
indicating an actual problem.

This is not a security issue since this page is not present in
production and user have to type something in the field but is better to
escape the input.

update the recommended ruby version.

print generators on failed generate

Correct Documentation for asset_tag_helpers

Refactor the type casting of booleans in MySQL

Remove checks against `column.type` in abstract adapter quoting

Add missing test case for quoting behavior

The intention is to eventually remove `column` from the arguments list
both for `quote` and for `type_cast` entirely. This is the first step
to that end.

Let's say we just ran:

```
$ rails g migrate add_click_to_issue_assignment
```

We will get an error that looks like:

```
Could not find generator migrate.
```

This patch adds all existing migrations to the output to make it easier for a developer to find a valid migration.

```
Could not find generator "migrate". Please select a valid generator:
Rails:
  assets
  controller
  generator
  helper
  integration_test
  mailer
  migration
  model
  resource
  scaffold
  scaffold_controller
  task
```


It would be nice to do some spelling detection and suggest alternatives, but for now this should  help.

It appears that the only time that `quote` is called with a column,
but without first calling `type_cast` is when where is called with an
array. My previous pull request broke this behavior, without failing
tests. This adds a test for the only case I can think of that exercises
the `if column.type == :integer` branch of `quote` effectively.

Add an interface for type objects to control Ruby => SQL

Adds the ability to save custom types, which type cast to non-primitive
ruby objects.