Typo fix in README.md
Add autofocus to login form

Springing from the discussion in https://github.com/spree/spree/issues/4715, this change allows the HTML5 `autofocus` attribute to put the cursor into the email field when displaying the login screen, which removes one step from the user login process.

Closes #190
Redirect to login page if the user is not logged in.
Fixes #177
Fix specs.
Changes for supporting guest_token cookie.
Kill all the decorators kill them all

Just had a spree 1-3-stable promo decorator dejavu, I wouldn't recommend
it to anyone. We have pretty much this same code in spree/spree already

see https://github.com/spree/spree/blob/2a2034f63717ebd58883a53849c96c8fae75da4d/frontend/app/controllers/spree/orders_controller.rb#L76-L85
Depend on Spree 2.4.0.beta