Merge branch 'hotfix/2.1.8'
Starting 2.1.9 hotfix branch
Show error instead of confirm message if order status notification could not be sent
Speed up variant check
CS
Order total was not shown in the backend order list (#1282)
Fixed misspelled method name (#1274)
Always load language files in postsale script (#1281)
Correctly format shipping addresses in checkout step (#1278)
The checkout login page is only necessary for member-only checkout
Delete a member's cart when the member is deleted (#1296)
Auto-clean old member carts too
Correctly select "use billing address" when shipping and billing address are the same
Shipping address was not available when billing address was automatically chosen (#1267)
Reports daily summary showed incorrect number of orders (#1268)
List of rules: wrong key "label" in DCA

I assume that the key `label` should be `format` in order to format the label string.
Show coupon input field, even if all available codes are used.

(1) The shop should not publicy leak if all available codes are used by
the user.
(2) The message "coupon was added" will never be shown if the last
available coupon was added.
Pass rules and used coupons to the template (#1300)
Added log messages when toggling visibility of product and download (#1310)
Transifex sync