make sure we load the promotion rules after initialize so the user rules are correctly saved. also remove the after_save on promotion, this is no longer needed.
[api] Passing without_children=1 to taxons endpoint will now return a 'shallow' result set without children

Fixes #4112
make sure we use the proper check for checkout steps to render the shipment state

Fixes #4107
Fix issue where checkout failing on confirm step would redirect back to address step

Fixes #4117
Create a payment for 'double clicking confirm' test in checkout_spec

This is now necessary to reach the confirm step, due to #4117
removing commented <h2> on admin area

Fixes #4109