This commit restores the ability to assign cookies for testing via
@request.env['HTTP_COOKIE'] and @request.cookies, e.g:

    @request.env['HTTP_COOKIE'] = 'user_name=david'
    get :index
    assert_equal 'david', cookies[:user_name]

and

    @request.cookies[:user_name] = 'david'
    get :index
    assert_equal 'david', cookies[:user_name]

Assigning via cookies[] is the preferred method and will take precedence
over the other two methods. This is so that cookies set in controller
actions have precedence and are carried over between calls to get, post, etc.

Assigning cookies for test cases should now use cookies[], e.g:

  cookies[:email] = 'user@example.com'
  get :index
  assert_equal 'user@example.com', cookies[:email]

To clear the cookies, use clear, e.g:

  cookies.clear
  get :index
  assert_nil cookies[:email]

We now no longer write out HTTP_COOKIE and the cookie jar is
persistent between requests so if you need to manipulate the environment
for your test you need to do it before the cookie jar is created.

Fixed while traveling to heuruko

Move SCSS generators and default templates from Rails to the Sass Railtie (d435726312601edb3ba6f97b34f562221f72c1f8).

* Sass gem registers a compressor
* Sass gem registers generators for assets and scaffold
* Create a default stylesheet_engine ("css") for apps that remove the Sass gem

Change compressor API so that plugins can register default compressors for their stylesheet or JS engines and still allow the user to turn off compression

Replace references to ActiveSupport::SecureRandom with just SecureRandom, and require 'securerandom' from the stdlib when active support is required.

Also, no need to include dependencies in AS::Concerns inside included blocks.