Reimbursement email

cherry-picked from bab9726882db821bd4100a9aebecb37f424f6416 in spree master
Display return acceptance errors in Admin UI

So admins know what rule caused an item to be rejected or placed in the manual_intervention_required state.

cherry-picked from 1e60ad41cbcabbc7291db6c701ff4389687e9854 in spree master
Add preference for automatically restocking returned items

cherry-picked from 17eda30a7ff9f59826f99397b111b6a9a421f633 in spree master
Credit Reimbursement Type

cherry-picked from 59ff3cceb6f7f4df7abc0efe0ea03e7212a953ee in spree master