Ensure option values in Variant#options_text are sorted in a predictable order

Fixes #2432
admin product edit: back to products list fix to preserve query params

Fixes #2431
Removed disableSelection() call which was causing problems in Firefox.

Fixes #2432
Changed scope for country name translations

This is done to avoid conflict with label for Spree admin configuration menu.
See issue #2420

Fixes #2421
Allow link_to_cart to be used outside of Spree context

Fixes #2441
Replace product lookups by permalink using where() with find_by_permalink()

This is to aid in compatibility with globalize3

Fixes #2439
Remove not required from main scss stylesheet. Fixes #1963

Fixes #2438