Give USPS Priority Mail Medium Flat Rate Box class file to correct name
Use friendly_id searchers in product_packages_controller and products_controller_decorator
Fix for already initialized constant errors

Fixes #176
Fixes #147
Fixes #75
Guard against missing shipping_method calculators

Fixes #176
Fixes #174
Fixes #75
Merge remote-tracking branch 'upstream/2-2-stable' into 2-2-stable

Conflicts:
	lib/spree_active_shipping/engine.rb
remove OriginAddress setting