If an attribute was of the binary type, and also was a Hash, it would
previously not be logged, and instead raise an error saying that
`bytesize` was not defined for the `attribute.value` (a `Hash`).

Now, as is done on 4-2-stable, the attribute's database value is
`bytesize`d, and then logged out to the terminal.

Reproduction script:

```ruby
require 'active_record'
require 'minitest/autorun'
require 'logger'

ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :posts, force: true do |t|
    t.binary :preferences
  end
end

class Post < ActiveRecord::Base
  serialize :preferences
end

class BugTest < Minitest::Test
  def test_24955
    Post.create!(preferences: {a: 1})

    assert_equal 1, Post.count
  end
end
```

Minor syntax change

While working on this very example recently, I found that Rails will throw POST errors if you leave an empty block in front the `format.js` when using either `remote: true` or vanilla  JS/JQuery.

Should quote `lock_name` to pass to `get_advisory_lock`

Replacement cycle for readability

Fix Gemfile.lock by updating rails-dom-testing

- Followup of https://github.com/rails/rails/pull/24946.

Update rails-dom-testing gem to 2.0

Resolves #24924.

use Rack::Utils.valid_path? to check path

Improve AV changelog with regards to default RAW handler

Feature getting started guide [ci skip]

It highlights which kind of incompatibilities this could lead to when rendering plain JS or HTML partials.

Add :ssl/:tls to ActionMailer rdoc [ci skip]

WIP: Action Cable JavaScript tests

Will be using this in later code.

Each test executes in another tmp folder, so there's no chance
of polluting another test run.

This commit uses the new method in Rack to check if a path is valid.

Replacement cycle for readability

Change http github links to https [ci skip]

Use consistent term `underscored`

Use original `Array#sum` when calculating Numeric sum.
This commit is related #24804 issue.
Issue #24804 reports `Array#sum` becomes much slower when
ActiveSupport is included.

This commit tries to use original method as far as possible.

```shell

$ cat array_sum.rb
class Array
  alias core_sum sum
end

require 'benchmark/ips'
require 'active_support/core_ext/enumerable'

ary = [1.0] * 1_000_000

Benchmark.ips do |x|
  x.report("core sum") { ary.core_sum }
  x.report("AS's sum") { ary.sum }

   x.compare!
end

$ bundle exec ruby -v -I lib array_sum.rb
ruby 2.4.0dev (2016-05-01 master 54867) [x86_64-darwin14]
Calculating -------------------------------------
            core sum     4.000  i/100ms
            AS's sum     5.000  i/100ms
-------------------------------------------------
            core sum     50.492  (± 7.9%) i/s -    252.000
            AS's sum     50.116  (± 6.0%) i/s -    250.000

Comparison:
            core sum:       50.5 i/s
            AS's sum:       50.1 i/s - 1.01x slower
```
Signed-off-by: NJeremy Daer <jeremydaer@gmail.com>

Follow up to 7d55c846

Followup to #24844

Some slight documentation edits and fixes. Also, run remove unnecessary
`RuntimeError`.

r? @arthurnn

In #23935, cable file was to be provided by the javascript instead of coffeescript,
doc was also been modified to use javascript.

Replace `loop` to `until`