Avoid name clashing when including modules
Allow assigning shipped_at to shipments.

Conflicts:
	core/spec/lib/spree/core/importer/order_spec.rb
Merge pull request #5101 from themetric/fix-api-custom-template

add missing respond_with to some API controllers and add tests
Merge pull request #4844 from woboinc/bugfix/avoid_name_clashing

Avoid name clashing when including modules
add validation to verify that count_on_hand of backorderable should not go negative if it is not backorderable

Fixes #3808
add a before_transition to verify if order is resumed only if there are no insufficient stock lines
Fixes #3819

Conflicts:
	core/app/models/spree/order/checkout.rb
Fix conflict.
Reload to make sure shipment.inventory_units have the latest status so that shipment.backordered? return correct value
Fixes #5163
Merge branch '2-2-stable' into 2-2-nemo-stable

Conflicts:
	core/spec/models/spree/stock_item_spec.rb