Improve build.sh output

- Add "--quiet" to "bundle update" to silence gem output
- Highlight the beginning of each suite more with some asterisks

Conflicts:
	build.sh

cherry-picked from 6323447f51a86b82843f3c4bed236dfc6aae8515 in master
Reimbursements model & Manual intervention resolution for Returns

- New Reimbursement model which encapsulates the concept of reimbursing a set of accepted return items, which will be reimbursed via one or more reimbursement methods (e.g., refunds, exchanges, store credits, etc)
- Moved refund logic from customer return into Reimbursement
- Ability to resolve "manual_intervention_required" returns items in the Admin UI
- Provide preview of how reimbursements will be parceled out before performing them
- Add a default "ReimbursementPerformer" that figures out how to distribute a reimbursement

Other enhancements/fixes:

- Suggested amounts now update on input changes
- Add generic "success/notice/error" state colors
- New Admin show page for customer returns
- Remove customer return refund endpoint
- new Admin ReimbursementsController & ReturnItemsController

Conflicts:
	core/app/models/spree/customer_return.rb
	core/app/models/spree/return_authorization.rb
	core/spec/models/spree/customer_return_spec.rb

cherry-picked from a6755a7f0fe3b2c99a026dea309ff9fbdc498c68 in master