Improve js written for guides

* Stop using unnecessary global variable
* Use function defined by jQuery for simplicity
* Fix event listner for "more info button" to handle
  event on resize browser
Add few information about missing steps [ci skip]

Add some deprecations previously note covered such as the confirm
option for the link_to helper or options which aren't needed anymore

Also add a mention about the config.assets.js_compressor option.
cookies are encrypted starting Rails 4
doc for more input tag types
Complete a sentence in i18n guide's introduction

Add a list of what will be covered into this guide
Removed params permit step from 5.6 section [ci skip]
Document where `column` param gets utilized in `substitute_at`.
[doc] fixed printing of code samples
remove deprecated `PostgreSQLAdapter#outside_transaction?` method.
cleanup, remove trailing whitespace from guides/CHANGELOG
Removed deprecated threadsafe!
Merge pull request #11279 from jetthoughts/removed_threadsafe_deprectaed_option

Removed deprecated threadsafe! from Rails Config
Added missing CHANGELOG from PR #11279 [ci skip]
Merge pull request #11280 from arunagw/added-missing-changelog-entry

Added missing CHANGELOG from PR #11279 [ci skip]
Removed unused deprecation requires.
Merge pull request #11281 from jetthoughts/remove_unused_deprecation_requires

Removed unused deprecation requires.
method transplanting between modules isn't supported on 1.9
removed deprecated increment_open_transactions
Remove deprecated `decrement_open_transactions`.
Remove deprecated `transaction_joinable=`

in favor of `begin_transaction`
with `:joinable` option.