Fix grammar in Getting Started with Rails

Fix default connection handling with three-tier config

In a three-tier config environment
`configurations[environment].presence` will return `{ :primary => {
:key => value, :key => value }, :secondary => { :key => value, :key =>
value} }, which means it's not given a single config to connect to.

If we flip these however it will connect to primary because that's the
default connection, and on a two tier it will be `nil` so the code will
select the connection from the configurations rather than the
connection.

If you had a three-tier config, the `establish_connection` that's called
in the Railtie on load can't figure out how to access the default
configuration.

This is because Rails assumes that the config is the first value in the
hash and always associated with the key from the environment. With a
three tier config however we need to go one level deeper.

This commit includes 2 changes. 1) removes a line from `resolve_all`
which was parsing out the the environment from the config so instead of
getting

```
{
  :development => {
    :primary => {
      :database => "whatever"
    }
  },
    :animals => {
      :database => "whatever-animals"
    }
  },
  etc with test / prod
}
```

We'd instead end up with a config that had no attachment to it's
envioronment.

```
{
  :primary => {
    :database => "whatever"
  }
  :animals => {
    :database => "whatever-animals"
  }
  etc - without test and prod
}
```

Not only did this mean that Active Record didn't know how to establish a
connection, it didn't have the other necessary configs along with it in
the configs list.

So fix this I removed the line that deletes these configs.

The second thing this commit changes is adding this line to
`establish_connection`

```
spec = spec[spec_name.to_sym] if spec[spec_name.to_sym]
```

When you have a three-tier config and don't pass any hash/symbol/env etc
to `establish_connection` the resolver will automatically return both
the primary and secondary (in this case animals db) configurations.
We'll get an `database configuration does not specify adapter` error
because AR will try to establish a connection on the `primary` key
rather than the `primary` key's config. It assumes that the
`development` or default env automatically will return a config hash,
but with a three-tier config we actually get a key and config `primary
=> config`.

This fix is a bit of a bandaid because it's not the "correct" way to
handle this situation, but it does solve our immediate problem. The new
code here is saying "if the config returned from the resolver (I know
it's called spec in here but we interchange our meanings a LOT and what
is returned is a three-tier config) has a key matching the "primary"
spec name, grab the config from the spec and pass that to the
estalbish_connection method".

This works because if we pass `:animals` or a hash, or `:primary` we'll
already have the correct configuration to connect with.

This fixes the case where we want Rail to connect with the default
connection.

Coming soon is a refactoring that should eliminate the need to do this
but I need this fix in order to write the multi-db rake tasks that I
promised in my RailsConf submission. `@tenderlove` and I are working on
the refactoring of the internals for connection management but it won't
be ready for a few weeks and this issue has been blocking progress.

[ci skip]

[ci skip]

* Check exclude before flagging cookies as secure.

* Update comments in ActionDispatch::SSL.

[Catherine Khuu + Rafael Mendonça França]

Only preload misses on multifetch cache

Partly revert #32231

Fix typo in active_job_basics.md

`it's` -> `its`

It's causing a test to fail.
Ref: https://travis-ci.org/rails/rails/jobs/353758855#L1433-L1501

Time column improvements

Don't marshal ActiveSupport::Cache::Entry objects twice

When upgrading to Rails 5.2 we're seeing
`ActiveSupport::Cache::Entry#compress` and
`ActiveSupport::Cache::Entry#should_compress?` as the highest usage of
our CPU. At least some part of this is coming from the fact that objects
are being marshaled multiple times. This memoizes the marshaled value to
eliminate half the problem.

Merge pull request #32250 from bogdanvlviv/add-info-about-exprity-of-siigned-cookies-to-upgrading-to-5-2

Update "Upgrading from Rails 5.1 to Rails 5.2" [ci skip]

Add section "Expiry in signed or encrypted cookie is now embedded in the cookies values"
to `master` since it should always be in the guides, not only for version 5.2.

Add info about `config.action_dispatch.use_authenticated_cookie_encryption`
to the "Configuring Rails Applications" guide.

It was committed straight  to `5-2-stable` since we don't need this
functionality in 6.0. Related to b25fcbc0.

Fixes #32248.

- Remove extra execution of `perform_enqueued_jobs`
  since it performs all enqueued jobs in the duration of the block.
- Fix example of using `assert_emails` without block since we
  can't use enqueued jobs in this case.

Fix routing inspector tests broken in https://github.com/rails/rails/commit/6629d51a2756fadf961bb09df20579cacfef2c8e

* Renames grep_pattern to grep throughout.
* Fixes setup not calling super by calling setup with a block.
* Converts test helper method to a private one, like we have it other places.
* Uses keyword arguments to get around awkward draw({ grep: "x" }, Action…)
  construction.

We end up with:

```
Usage:
  bin/rails routes [options]

Options:
  -c, [--controller=CONTROLLER]      # Filter by a specific controller, e.g. PostsController or Admin::PostsController.
  -g, [--grep=GREP]                  # Grep routes by a specific pattern.
  -E, [--expanded], [--no-expanded]  # Print routes expanded vertically with parts explained.
```

which does miss the bit about routes being printed in order.

Also:

* Renames options to ease help output readability, then clarifies each option.
* Fixes a bunch of indentation.

We only add the header when releasing to avoid some conflicts.

[ci skip]

Perform email jobs in #assert_emails

Change message on the empty result of searching routes by `rails routes` with `-c` or `-g` 

Update "Ruby on Rails 5.2 Release Notes" Guide [ci skip]

- Add a description of major features in Rails 5.2.
- Add a reference to Pull Request/Commit to every entry in CHANGELOGs,
  note that some of them combined.
- Add section "Ruby on Rails Guides" with notable changes.
- Note that
  - Skipped this since encrypted secrets are already on the way out.
    ```
    *   Add `rails secrets:show` command.
        ([Pull Request](https://github.com/rails/rails/pull/29695))
    ```
  - Skipped this since it was backported all the way to 5-0-stable.
    ```
    *   Make Rails' test runner work better with minitest plugins.
        ([Pull Request](https://github.com/rails/rails/pull/29572))
    ```

Thanks to everyone who has been working on Rails 5.2! <3

- Create `Base` and inherit `Sheet` and `Expanded` in order to
- prevent code duplication.
  - Remove trailing "\n" for components of `Expanded`.
  - There is no need for `Expanded#header` to return `@buffer` so return `nil` instead.

- Change `no_routes` message "No routes were found for this controller"
  since if use `-g`, it sounds incorrect.
  - Display `No routes were found for this controller.` if apply `-c`.
  - Display `No routes were found for this grep pattern.` if apply `-g`.

Related to #32130

- Add a mention about `-g`.
- Improve info about `--expanded` option of `rails routes`.

Since `Redis#call` duck types as a Proc, we'd call `#call` on it,
thinking it's a Proc. Fixed by check for the Proc explicitly instead of
duck typing on `#call`.

References #32233

Follow up of 309bb6c4

Perform enqueued delivery jobs in #assert_emails and #assert_no_emails.

The Active Storage service for Azure Storage has an option called `path`
that is ambiguous in meaning. It needs to be set to the primary blob
storage endpoint but that can be determined from the blobs client anyway.

To simplify the configuration this commit removes the `path` option and
gets the endpoint from the blobs client instead.

Closes #32225.