Generic cast-to-text was only added in 8.3.

PERF: Don't create a Relation when it is not needed.

Typo fix (ci skip)

`lengh` should be `length`  

Add require to ensure Time#advance works without implicit required

Use global migrations_path configuration in Migrator

Fix strange messages for `rails g foo`

Benchmark script used:
```
begin
  require 'bundler/inline'
rescue LoadError => e
  $stderr.puts 'Bundler version 1.10 or later is required. Please update your Bundler'
  raise e
end

gemfile(true) do
  source 'https://rubygems.org'
  gem 'rails', path: '~/rails' # master against ref "f1f0a3f8"
  gem 'arel', github: 'rails/arel', branch: 'master'
  gem 'rack', github: 'rack/rack', branch: 'master'
  gem 'sass'
  gem 'sprockets-rails', github: 'rails/sprockets-rails', branch: 'master'
  gem 'sprockets', github: 'rails/sprockets', branch: 'master'
  gem 'pg'
  gem 'benchmark-ips'
end

require 'active_record'
require 'benchmark/ips'

ActiveRecord::Base.establish_connection('postgres://postgres@localhost:5432/rubybench')

ActiveRecord::Migration.verbose = false

ActiveRecord::Schema.define do
  create_table :users, force: true do |t|
    t.string :name, :email
    t.timestamps null: false
  end
end

class User < ActiveRecord::Base; end

attributes = {
  name: "Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
  email: "foobar@email.com",
}

1000.times { User.create!(attributes) }

Benchmark.ips(5, 3) do |x|
  x.report('all') { User.all }
end

key =
  if RUBY_VERSION < '2.2'
    :total_allocated_object
  else
    :total_allocated_objects
  end

before = GC.stat[key]
User.where(name: "Lorem ipsum dolor sit amet, consectetur adipiscing elit.")
after = GC.stat[key]
puts "Total Allocated Object: #{after - before}"

```

Before:
```
Calculating -------------------------------------
                 all    17.569k i/100ms
-------------------------------------------------
                 all    190.854k (± 3.3%) i/s -    966.295k
Total Allocated Object: 85
```

After:
```
Calculating -------------------------------------
                 all    22.237k i/100ms
-------------------------------------------------
                 all    262.715k (± 5.5%) i/s -      1.312M
Total Allocated Object: 80
```

safe_constantize - Added Object scoped missing test cases

adding description of return value [ci skip]

[ci skip] Replace `AR` with `Active Record` in task desc

Many user look `desc` of rake task and they are not familiar with `AR`.
`Active Record` is more familiar word.

Apparently I managed to forget how similar the "tests passing" and
"no status reported" merge indicators look.

Note that the previous `stubs` in test_add_index wasn't working:
the method was still called, and just happened to return false.

Support dropping indexes concurrently in Postgres

Deprecate passing conditions to AR::Relation destroy_all and delete_all methods

Removed Extra ‘the’ [ci skip]

`hfvalue` parts should always be percent encoded, so lets do that!

Revert "use path escaping for email addresses"

This reverts commit 21ffef38.

Remove mocha from ActionPack tests

See http://www.postgresql.org/docs/9.4/static/sql-dropindex.html
for more details.

converts old ID methods to the new abstract store methods in Rack

Just include the modules necessary in the Request object to implement
the things we need.  This should make it easier to build delegate
request objects because the API is smaller

#where fails if opts.responds_to?(:==) unexpectedly

Sometimes opts passed in might respond to ==, e.g. `Arel::Nodes::Grouping`. In this case, `opts == :chain` returns `Arel::Nodes::Equality` which causes odd behaviour. Prefer `if :chain == opts` which guarantees that `Symbol#==` would be invoked. Alternatively consider `eql?`.

Due to e25fdad2, we are correctly using
path escaping for email addresses.  This commit fixes the tests to
expect path escaping.

Escaping and unescaping paths is different than query parameters, and we
need to respect that.  This commit uses the new method in Rack to escape
and unescape paths.  Fixes #11816

Add detailed error message to `IrreversibleMigration`

fix module name typo in API app guide [ci skip]

Update Unicode Version to 8.0.0

Remove unnecessary require in associations_test.rb

Removed unused config from activemodel test