A FeatureToggle could be switched via a class_eval in an initializer.
The initializer was installed via ofn-install. We want to get rid of
custom, untracked initializers. Here I'm changing the FeatureToggle
class to use environment variables instead.
This change needs to be followed up with a change in ofn-install to use
the new environment variable. It affects only Australian production.
This removes ten old overrides of the Spree view. Since the Spree view
is not used any more and got completely replaced by custom views, the
overrides were just adding noise to the code base.
