dash depends on backend, not frontend
Fix stylings for select2 boxes and other admin misc.
[api] Add params[:ids] support to products
[backend] Use API for product searching
Move Spree:ActionCallbacks to Backend
Move Spree::BaseController to Core

This is so frontend and backend can use it independently of each other
Move admin layout from frontend to backend + move helpers into core
Remove definition of ajax-root-path from admin layout

This is simply not referenced in any code
Allow backend locale to be set independently