Redid the product packages admin interface. Brought it up to the new admin standard from 1.3.

The new and edit commands function like the images new command.

Wasn't a clean merge because of the Spree 2.0 translations

Signed-off-by: Nathan Lowrie <nate@finelineautomation.com>

Conflicts:
	app/controllers/spree/admin/product_packages_controller.rb
	app/models/spree/product_decorator.rb
	app/views/spree/admin/product_packages/index.html.erb
	config/locales/en.yml