Revert credit card stripping from #1881

For reasons why, please see the thread on #2495.

Conflicts:
	core/app/models/spree/credit_card.rb
G Analytics apparently not using protocol specific subdomain now.

Fixes #2977
Remove Payment#amount_is_valid_for_outstanding_balance_or_credit which is not being used anywhere.

Fixes #2978
Remove some space from tables cells

Fixes #2968
Adding methods for inserting and removing checkout steps for an order

Fixes #2969