analytics annonymous user_id
adds after validation and if empty
uuid is set when blank?
added tracking cookie

Conflicts:
	lib/controllers/backend/spree/admin/user_sessions_controller.rb
guest user tracking

Conflicts:
	app/models/spree/user.rb
	lib/controllers/frontend/spree/checkout_controller_decorator.rb
added missing tracking cookie updater

Conflicts:
	app/controllers/spree/checkout_controller_decorator.rb