Second try on this commit.

TextHelper#simple_format attempts to call undefined raw method

Fix AR#method_missing re-dispatching into overwritten attribute methods

Conflicts:
	activerecord/lib/active_record/attribute_methods.rb

Now users have to explicit mark the unit as safe if they trust it.

Closes #13161

Conflicts:
	actionpack/lib/action_view/helpers/number_helper.rb
	actionpack/test/template/number_helper_i18n_test.rb

Follow up to #12958.

Install Spring preloader when generating new applications

Added JSON related items to the 4.1 release notes

Avoid one-liner conditionals when they are too big. Avoid concatenating
strings to build error messages. Improve messages a bit.

Action Pack Variants

By default, variants in the templates will be picked up if a variant is set
and there's a match. The format will be:

  app/views/projects/show.html.erb
  app/views/projects/show.html+tablet.erb
  app/views/projects/show.html+phone.erb

If request.variant = :tablet is set, we'll automatically be rendering the
html+tablet template.

In the controller, we can also tailer to the variants with this syntax:

  class ProjectsController < ActionController::Base
    def show
      respond_to do |format|
        format.html do |html|
          @stars = @project.stars

          html.tablet { @notifications = @project.notifications }
          html.phone  { @chat_heads    = @project.chat_heads }
        end

        format.js
        format.atom
      end
    end
  end

The variant itself is nil by default, but can be set in before filters, like
so:

  class ApplicationController < ActionController::Base
    before_action do
      if request.user_agent =~ /iPad/
        request.variant = :tablet
      end
    end
  end

This is modeled loosely on custom mime types, but it's specifically not
intended to be used together. If you're going to make a custom mime type,
you don't need a variant. Variants are for variations on a single mime
types.

This reads a lot better, and we won't need to try start_with? for blank
delimiters.

Also rename method name to read better.

The conversion without area code already changed the passed number in
place, so change the other method to do the same.

Improve formatting of ActiveRecord migration exception messages

Fix offset with last.

We are generating safe strings in the paragraph, so we can escape the
tags

Closes #7441

* master-sec:
  Deep Munge the parameters for GET and POST
  Stop using i18n's built in HTML error handling.
  Ensure simple_format escapes its html attributes
  Escape the unit value provided to number_to_currency
  Only use valid mime type symbols as cache keys

Closes #13146.

This fixes an error when using:

```
change_colum :table, :column, :bigint, array: true
```

Added Date#all_week/month/quarter/year for generating date ranges