Fix simple_format output example ending tag

Closes #11248.

Creating a class to handle preparing ARGV.

The standard Ruby behavior for Time.at is to return the same type of
time when passing an instance of Time as a single argument. Since the
an ActiveSupport::TimeWithZone instance may be a different timezone than
the system timezone and DateTime just understands offsets the best we
can do is to return an instance of Time with the correct offset.

Fixes #11350.

When Time.at_with_coercion (wraps Time.at) is called with a single
argument that "acts_like?(:time)" it is coerced to integer thus losing
it's microsecond percision.

This commits changes this to use `#to_f` to prevent the problem

Before the AppGenerator is started, ARGV needs to be modified to
correctly account for some things. I'm extracting these out into their
own class.

Using the instance variable for argv.

Instead of using the global constant ARGV, we're changing to using the
instance variable because it is more testable.

Fix: attribute_for_inspect truncate upto (51 => 50) characters.

Stop sending column info to `substitute_at` as it doesn't get utilized.

Improve guides js

Add few information about missing steps [ci skip]

cache.exists? should return true/false

Use content_length method instead of ENV['CONTENT_LENGTH'].to_i

Use Request#raw_post instead Request#body in ParamsParser#parse_formatted_parameters

Added cursor pointer for 'More Ruby on Rails' dropdown menu on guides page (which appear on small windows)

Fixed Travis CI link for rails

Remove redundant test about `push_with_attributes` removal.

link break added after the Travis CI link

Actionview changes

Also added actionview to update version rake task

Fix a grammatical error/typo in Active Record Migrations guide. [ci skip]

the connection

Creating a class for carrying out rails commands.

handle notes in *.sass files

Fix 2 grammatical errors/typos in Active Record Basics guide. [ci skip]