Make remote_ip detection properly handle private IPv6 addresses

Fixes #12638.
SQLite3: Always close statements.

SQLite3 adapter must make sure to close statements after queries.

Fixes: #13631
[ci skip] Added example for email_field_tag method
[ci skip] Added example for date_field_tag method
[ci skip] Added example for number_field_tag method
Remove reference to outdated section 

[ci skip]
update doc, assert_template also accepts false

[ci skip]
Document ActionController::TestCase::Behavior::ClassMethods.process

[ci skip]
Running AR tests on postgres, mysql & sqlite

[ci skip]
Revert "update doc, assert_template also accepts false"

This reverts commit 9b1c077c91f09b64b8105f31fdf5240cd12c2e16.

my bad.
`assert_template` only accepts a String, Symbol, Hash, Regexp or nil.

`false`(layout: false) is provided as a Hash.
Revert "Revert "update doc, assert_template also accepts false""

Reason: docrails policy is very strict about code. No matter how
innocent the change, if it is not documentation it needs to go
through a PR to rails/rails.

Plase see the warning box at the bottom of

    http://edgeguides.rubyonrails.org/contributing_to_ruby_on_rails.html#contributing-to-the-rails-documentation

This reverts commit e1c5d24369440857de1402d61c85d982b29d8019.
Revert "Revert "Revert "update doc, assert_template also accepts false"""

Revert Festival!

I reverted a reverted commit, undo.

This reverts commit 07ea37763d62e57d5709ab37da01b2848d12edd5.
Grammar and formatting fixes in Form Helpers Guide

Improved version of #14851 after helpful feedback from @robin850 and @matthewd.

[skip ci]
Warning removed for missmatched indentation
Fix documentation of extract_handler_and_format_and_variant [ci skip]
Merge pull request #14875 from prathamesh-sonpatki/fix-extract-handler-format-variant-doc

Fix documentation of extract_handler_and_format_and_variant [ci skip]
Merge pull request #14874 from arunagw/aa-warning-removed-missmatched

Warning removed for missmatched indentation
Merge pull request #14872 from jonatack/patch-7

Grammar and formatting fixes in Form Helpers Guide
Generators, remove leftover variable assignment. refs #14877

The last uses of this variable was removed with the `--builder` option.
  2da5ea1c9feb4a7b491bd00bd6ffd931b9203da8
Revert "Document ActionController::TestCase::Behavior::ClassMethods.process"

This reverts commit 2aef9fddf8b4487a05638ea3341dfd65ceb229ef.

Reason: The added change isn't clear in terms of explaining the
arguments. Will ask the author to provide a PR and take it forward.

[ci skip]